Technology posts

The humble ERC20 token specification has become the de facto standard for Ethereum tokens. If you come across an Ethereum smart contract, chances are it’s ERC20-compliant.

In this guide, Toptal Freelance Ethereum Developer Gilad Haimov demonstrates how you can create and deploy your own ERC20 token in under an hour.

The existence of RESTful APIs is a popular myth in web development—but it’s a myth we can work with. The right tools can help keep documentation consistent and streamline automated testing. In this article, Toptal Freelance JavaScript Developer Alexander Zinchuk explores several time-saving approaches to developing REST APIs, with examples in Node.js and Ruby on Rails.

There are two dominant patterns of implementation for inversion of control. Which one is better, and is there a middle path to be found between them? How should you approach IoC to get the most out of your code?

Join Toptal Java Developer Martin Coll in exploring the familiar and unknown landscape of IoC development.

Manually gathering information about user-generated data is time-consuming, to say the least. That’s why more organizations are turning to automatic sentiment analysis methods—but basic models don’t always cut it. In this article, Toptal Freelance Data Scientist Rudolf Eremyan gives an overview of some sentiment analysis gotchas and what can be done to address them.

The Raspberry Pi is a little computer that you can get for as low as USD $5 and on which you can run many different types of software and build many different projects. In this article, I’m going to guide you through the process of setting it up as a home development server and deploying a full-stack JavaScript application that you can access from outside your network. This is great for setting up your own remote digital workspace, or simply to have control over the hardware you use for development.

ClojureScript and its multiparadigm approach (with an emphasis on functional programming) may sound esoteric to some front-end developers. But it’s amazing to work with, and getting started with it is far simpler than one might imagine. In this tutorial, Toptal Freelance Clojure Developer Luke Tomlin shows off some key features, getting straight into a React demo using Reagent and the Hiccup syntax.

Augmented reality and virtual reality are becoming mainstream and easily available.

In this article, Toptal Freelance iOS Developer Altaibayar Tseveenbayar showcases a demo app for adding virtual objects to a video feed using ARKit.

There’s no question that user experience is impacted by perceived load times. With today’s heavier front ends, client-side rendering doesn’t feel very fast. In this article, Toptal Freelance Front-end Developer Guillaume Breux compares client-side, server-side, and pre-rendering strategies to help you choose the best option for your own app.

Angular 6 is out! The most outstanding changes are in its CLI and how services get injected. In this tutorial, Toptal Freelance Angular Developer Joaquin Cid goes over the basic steps of initial setup and then creates a small diary app using Material Design for the front end and Firebase for the back end.

Will AI make improve our lives beyond comparison, or will it steal our jobs and destroy humanity?

In this article, Dr. Necati Demir, Toptal Freelance AI Expert, discusses not the evil artificial general intelligence of science fiction but the current algorithm-based prediction AI and discusses how the economics of AI work, along with their effects on businesses.

The Ethereum Name Service is a blockchain-backed alternative to the internet’s traditional Domain Name System. If you own a .eth domain, you can deploy smart contracts that let users set up their own subdomains—but then, of course, you’ll want a corresponding ĐApp to make it user-friendly. In this tutorial, Toptal Freelance Ethereum Developer Radek Ostrowski provides complete coverage of this scenario, this time with a focus on ĐApp development.

Static websites offer a host of advantages over dynamic pages in many scenarios, but they can be impractical and tedious to maintain.

In this, Toptal Front-end Developer Silvestar Bistrovic demonstrates how the four most popular static page generators can help.

Hybrid mobile apps may have their limitations, but often it’s well worth the boost in cross-platform consistency and development speed. Apps made with Apache Cordova in particular can further leverage existing web developer skills through the use of Cordova frameworks. This tutorial compares Ionic with Framework7.

Leveraging DeepMind’s breakthrough AI approaches takes some work, but the results are astounding. In this article, Toptal Freelance Deep Learning Engineer Neven Pičuljan guides us through the building blocks of reinforcement learning, training a neural network to play Flappy Bird using the PyTorch framework.

Continuous integration using nothing but Apple tools used to be tedious and time-consuming. This changed with the launch of Xcode 9.0 last September.

In this article, Toptal iOS Developer Nemanja Stosic explains how you can harness the potential of new Xcode features to streamline iOS development.

As patterns go, REST APIs are so useful and ubiquitous that every web developer, regardless of language or platform, should know how to build one.

In this article, Toptal Freelance JavaScript Developer Marcos Henrique da Silva shows how to create a simple and secure REST API for user management on Node.js.

The Protein Data Bank (PDB) bioinformatics database is the world’s largest repository of experimentally-determined structures of proteins, nucleic acids, and complex assemblies. All data is gathered using experimental methods such as X-ray, spectroscopy, crystallography, NMR, etc. This article explains how to extract, filter, and clean data from the PDB to make it suitable for further analysis.

CSS is notorious for getting messy quickly as a website scales. While frameworks like Bootstrap can help, SMACSS takes a different approach, as a set of solid organizational guidelines. In this article, Toptal Freelance Front-end Developer Slobodan Gajic gives us a run-down of the idea and benefits behind Jonathan Snook’s architectural wisdom.

Employing Python to make machine learning predictions can be a daunting task, especially if your goal is to create a real-time solution. However, Tensorflow and Scikit-Learn can significantly speed up implementation.

In this article, Toptal Python Developer Guillaume Ferry outlines a simple architecture that should help you progress from a basic proof of concept to a minimal viable product without much hassle.

Many businesses use SharePoint but use it poorly. Restructuring and re-education are the keys to getting the most out of SharePoint. In this article, Toptal Freelance SharePoint Developer Anthony Lucidi explores how features like metadata tags, SharePoint workflows, and PowerApps can make a world of difference.

In this article, Toptal Freelance JavaScript Developer Nick Chikovani shows how easy it is to perform web scraping using a headless browser. Specifically, he provides a Puppeteer tutorial, going through a few examples of how to control Google Chrome to take screenshots and gather structured data.

How do you approach machine learning problems? Are neural networks the answer to nearly every challenge you may encounter?

In this article, Toptal Freelance Python Developer Peter Hussami explains the basic approach to machine learning problems and points out where neural may fall short.

Hot module replacement is one of the most useful features offered by Webpack. It allows all kinds of modules, including JSON, CSS, and JS files, to be updated at runtime without needing a full refresh.

In this article, Toptal Freelance JavaScript Developer Shaojiang Cai demonstrates how to use Hot Module Replacement in Redux.

ASP.NET Core is a leaner and more modular redesign of ASP.NET 4.x.

In this article, Toptal Freelance ASP.NET Developer Damir Imangulov shows how to build a robust RESTful API using ASP.NET, EF Core, AutoMapper, and XUnit.

Crystal is an up and coming programming language that should appeal to Ruby veterans in demand for more performance and flexibility. It may even be the most promising programming language of 2018.

In this tutorial, Toptal Ruby Developer Eqbal Quran demonstrates how you can harness Crystal’s potential to create your own blockchain and cryptocurrency.

Machine learning and artificial intelligence are popular topics, vast domains with multiple paradigms to solve any given challenge.

In this article, Toptal Machine Learning Expert Adam Stelmaszczyk walks us through implementing deep Q-learning, a fundamental algorithm in the AI/ML world, with modern libraries such as TensorFlow, TensorBoard, Keras, and OpenAI Gym.

Microsoft and Google have worked together since Angular 2, rendering ASP.NET Web Forms and MVC Razor obsolete. Nevertheless, while ASP.NET’s front-end tools may be lacking, it is still a great back-end framework.

In this article, Toptal Freelance Angular Developer Pablo Albella teaches us how to create the best architecture for both these worlds.

JSON web tokens (JWTs) provide a method of authenticating requests that’s convenient, compact, and secure. More often than not, Angular apps will include them in their data flows.

In this tutorial, Toptal Freelance Software Engineer Sebastian Schocke shows how to implement JWT authentication in an Angular 6 single-page application (SPA), complete with a Node.js back-end.

C++ developers strive to build robust multithreaded applications, but multithreading was never an easy thing to do.

In this article, Toptal Freelance Qt Developer Andrei Smirnov talks about several scenarios exploring concurrent programming with the Qt framework.

The modern, cross-platform programming language Haxe is well-known in some circles, yet many developers have never heard of it. Since it first appeared in 2005, it’s been battle-tested by its loyal—if rather quiet—following.

In this article, Toptal Freelance Software Engineer Kevin Bloch explores the Haxe ecosystem and how to transpile some sample code.

Despite its age, HTTP Live Streaming (HLS) remains a widely used standard in adaptive bitrate video and a de-facto Apple alternative to MPEG-DASH.

In this tutorial, Toptal Java Developer Tomo Krajina explains what makes HLS tick and demonstrates how to create an HLS player in Android.

The development of cross-platform mobile applications has always been a source of many challenges. Although tools like Apache Cordova and Haxe do solve some of the associated issues, they are still not the ideal solution in many cases. React Native changes that by providing the power of React.js for mobile platforms and a promise of consistent developer experience across multiple platforms.

Qmake is a build system tool shipped with Qt library that simplifies the build process across different platforms.

In this guide, Freelance Qt Developer Andrei Smirnov describes the most useful qmake features and provides real-world examples for each of them.

Computational photography is about enhancing the photographic process with computation. While we normally tend to think that this applies only to post-processing the end result (similar to photo editing), the possibilities are much richer since computation can be enabled at every step of the photographic process—starting with scene illumination.

In this article, Toptal OpenCV Expert Radu Balaban walks us through two examples of computational photography: low light and high dynamic range.

Threading is just one of the many ways concurrent programs can be built. In this article, we will take a look at threading and a couple of other strategies in building concurrent programs in Python, as well as discuss how each is suitable in different scenarios.

Mobile applications are creeping in. Developing for each mobile platform can be an exhaustive task, especially if resources are limited. This is where Apache Cordova comes in handy by providing a way to develop mobile applications using standard web technologies - HTML5, CSS3 and JavaScript. This article explores how one can get started with Apache Cordova and build mobile applications targeted at a wide range of mobile devices.

Software delivery has come a long way. And, somewhere between the transition from physical media to software containers, we have changed the way we try to manage them.

In this article, Toptal Freelance Software Engineer Jonathan Bethune explores how software containers have motivated us to treat servers as more dispensable, and the risks and rewards involved.

Deep learning has proven its power across many domains, from beating humans at complex board games to synthesizing music. It has also been used extensively in natural language processing.

In this article, Toptal Freelance Software Engineer Shanglun (Sean) Wang shows how easy it is to build a text classification program using different techniques and how well they perform against each other.

Spring Integration enables lightweight messaging within Spring-based applications.

In this article, Toptal Java Developer Adnan Kukuljac shows how Spring Integration with Redis makes it easy to build a microservice architecture.

Online users are becoming increasingly resistant to traditional email/password registration processes. One-click social logins via Facebook, Google, or GitHub are better, but they come with data privacy trade-offs.

This article introduces a one-click, cryptographically-secure login flow using MetaMask, with all data stored on the app’s own back-end.

Machine learning, combined with some standard image processing techniques, can result in powerful video analysis tools.

In this article, Toptal Freelance Software Engineer Michael Karchevsky walks through a solution for a machine learning competition that identifies the species and lengths of any fish present in a given video segment.

Dealing with a real database for integration and end-to-end testing can pose some challenges. One way of working around them is to use an in-memory database that integrates well with the testing framework and provides APIs to manipulate its state from test code.

In this article, Toptal Freelance Software Engineer Mikhail Angelov shows how you can write integration and end-to-end tests easily for your Node.js and MongoDB application without having to write complicated setup/teardown code.

Launch yourself into Ethereum smart contract development with the Truffle framework! In this tutorial, Toptal Freelance Ethereum Developer Radek Ostrowski shows you how to create a practical ĐApp in the Solidity language, complete with its own ERC20 token.

Open-source, IoT, and Ethereum smart contracts work together with a new utility coin to make transportation more accessible and reduce vehicle waste. In this article, Toptal Freelance Ethereum Developer Michał Mikolajczyk explains the motivations and methodology behind his startup’s latest initiative.

Mixed-integer programming is one of the many ways you can automate and enhance your decision-making processes.

In this article, Toptal Freelance Software Engineer Shanglun Wang explores the power of operations research by walking through a hypothetical problem and shows how mixed-integer programming can be used to solve it.

While machine learning sounds highly technical, an introduction to the statistical methods involved quickly brings it within reach. In this article, Toptal Freelance Software Engineer Vladyslav Millier explores basic supervised machine learning algorithms and scikit-learn, using them to predict survival rates for Titanic passengers.

Apache JMeter and REST Assured are two very popular Java-based tools for automated testing of REST API services.

In this article, Toptal Freelance Java Developer Nemanja Veskovic gives us an overview of the pros and cons of both of these tools and shows where they fit best in your existing REST API projects.

Non-Salesforce app developers may be overlooking a hidden gem in the AI world: Salesforce Einstein offers image recognition and text analysis for plain-vanilla apps and Salesforce apps alike. In this article, Toptal Freelance Salesforce Developer Fahad Munawar Khan shows how any any developer can leverage Einstein Vision and Einstein Language.

Asynchronous programming used to be a challenge even for seasoned professionals, leading to aptly named phenomena like Callback Hell.

In this article, Toptal JavaScript Developer Demir Selmanovic explains how async functions took us out of purgatory and why you should be using them.

Fragment caching in Rails provides an easy yet a powerful way of improving your application’s performance. However, some real-world scenarios do not work quite well with how the Rails cache behaves by default.

In this article, Toptal Ruby on Rails Developer Orban Botond shows how you can implement a small DSL to optimize how the cache for related entities is invalidated to improve template rendering performance.

Designing systems integration architecture can be a difficult task. And it gets worse if you’re designing for software at scale. An enterprise service bus can be one way of working around the challenges. But this is definitely not the simplest of solutions.

In this article, Toptal Freelance Software Engineer Anton Goncharov gives us a detailed overview of the challenges of systems integration and a guide to addressing those challenges with Apache Camel.

In this article, Toptal Freelance Software Engineer Neven Pičuljan introduces you to the intricacies of deep learning in hedge funds and finance in general.

In a recent project, there were several programmatic tasks I needed to repeat periodically. One task in particular involved updating user-level permissions based on evidence of membership level purchase or subscription.

Instead of going into the admin panel and manually deleting hundreds (maybe thousands) of subscriptions, I opted to reach for one of my favorite WordPress tools: WP-CLI, which fixed the problem in a few keystrokes.

The AI revolution is transforming the consumer world. Some developers may shy away from AI, which has traditionally been a heavily technical specialty. In this article, Toptal Freelance Salesforce Developer Fahad Munawar Khan explores how accessible to developers the AI cloud has become, even for non-Salesforce apps, with Salesforce Einstein.

Modern front-end frameworks constantly require you to download an entire development environment, complete with dependencies, and compile your code before even trying to view it on your browser. Is this something good? Is it the problem we are building more complex sites, or the frameworks are complex on their on own and they introduce an unnecessary level of complexity.

Working on an iOS application can be tedious, especially when you are wasting countless hours doing the most boring tasks: taking screenshots, signing code, and jumping through similar hoops to get your app to the users’ devices.

In this article, Toptal Freelance iOS Developer Francisco Reynolds walks you through the ultimate release automation tool for your iOS app and shows how it can save you from all of the tedious tasks.

Magento 2 was initially greeted with skepticism, but the maturity of the next generation of Magento development has brought on an explosion of new users. In this article, Toptal Freelance Magento Developer Vivek Khatri explains why it’s the top choice for eCommerce sites, new and old.

TensorFlow is more than just a machine intelligence framework. It is packed with features and tools that make developing and debugging machine learning systems easier than ever.

In this article, Toptal Freelance Software Engineer Dino Causevic gives us an overview of TensorFlow and some auxiliary libraries to debug, visualize, and tweak the models created with it.

AppExchange offers some solid wins for any company using Salesforce.

In this article, Freelance Salesforce Developer Fahad Munawar Khan explains how easy it is to get up and running with Salesforce AppExchange, and reveals some apps that are must-haves for any enterprise looking to boost their productivity.

TensorFlow makes implementing deep learning on a production scale a breeze. However, understanding its core mechanisms and how dataflow graphs work is an essential step in leveraging the tool’s power.

In this article, Toptal Freelance Software Engineer Oliver Holloway demonstrates how TensorFlow works by first solving a general numerical problem and then a deep learning problem.

Generative adversarial networks, among the most important machine learning breakthroughs of recent times, allow you to generate useful data from random noise. Instead of training one neural network with millions of data points, you let two neural networks contest with each other to figure things out.

In this article, Toptal Freelance Software Engineer Cody Nash gives us an overview of how GANs work and how this class of machine learning algorithms can be used to generate data in data-limited situations.

In this article, Toptal Freelance Magento Developer Daniel Cuevas Zamora gives a broad overview of one of the most popular eCommerce platforms and how to get started with it.

In this tutorial, Toptal Freelance Software Engineer John R. Kosinski will demonstrate a simple Amazon Alexa hack using quintessential Arduino skills and basic hardware.

In this article, Toptal Freelance Software Engineer Tiberius Florea outlines the difference between deep and broad skillsets and explains why broadening your skillset may further your career.

What is a computer? What are the limitations of a computer? Are there problems that a computer cannot solve?

In this article, Toptal Freelance Software Engineer Mehmet Bajin explores the fundamentals of computation and the impact they have on computability and complexity.

Flaws in your database design are like cracks in your application’s foundations. If left unchecked, trying to fix them down the line will be costly to say the least.

In this article, Toptal Freelance Software Engineer Fernando Martinez discusses some of the most common database design bad practices and how to avoid them.

In this article, Toptal Freelance Software Engineer Silvestar Bistrovic explains the process of migrating a WordPress blog to a static site generator using Hexo, outlining the pros and cons of the approach.

Elasticsearch is one of the most powerful full-text search engine solutions out there. Using the NEST package, you can easily leverage the power of Elasticsearch in your .NET projects.

In this article, Toptal Freelance Software Engineer Ivan Cesar shows how Elasticsearch can solve real-world full-text search problems in your .NET projects.

Do you think testing your iOS or Android apps manually is faster than writing automated tests for them? Calabash, the cross-platform acceptance framework, busts that myth once and for all.

In this article, Toptal Freelance Software Engineer Alexander Gedevanishvili shows how Calabash, with its support for Cucumber, makes writing automated UI tests as simple as writing instructions in plain English.

Complex, tightly-coupled, and fragile interdependent code. We’ve all written it. The kind of code where fixing one bug creates seven more. Have you ever wondered how to create independent modular code?

In this article, Toptal Freelance Software Engineer Konrad Gadzinowski walks us through the different types of architectural paradigms you can adhere to and how to write modular and decoupled code where changes to one module have minimal impact on the overall application.

In this article, Toptal Freelance Developer Adam Wasserman explains what software entropy is, what causes it and how it manifests itself, and what can be done to prevent it or mitigate its effects.

Serverless computing is an architecture style in which the code is executed in a cloud platform where we don’t need to worry about the hardware and software setup, security, performance, and CPU idle time costs. It’s an advancement of cloud computing that goes beyond infrastructure that abstracts the software environment as well. It means no configuration is required to run the code.

The Aho-Corasick algorithm can be used to efficiently search for multiple patterns in a large blob of text, making it a really useful algorithm in data science and many other areas.

In this article, Toptal Freelance Software Engineer Roman Vashchegin shows how the Aho-Corasick algorithm uses a trie data structure to efficiently match a dictionary of words against any text.

In this article, I will try to give you a good understanding of which scenarios could be covered by Celery. Not only will you see interesting examples, but will also learn how to apply Celery with real world tasks such as background mailing, report generation, logging and error reporting. I will share my own way of testing tasks beyond emulation and explain a few tricks that go beyond the official documentation and took me hours of research to discover myself.

WordPress is a very popular way to get a site up and running quickly. However, in their haste, plenty of developers end up making horrible decisions. Some mistakes, like leaving WP_DEBUG set to “true,” may be easy to make. Others, like lumping all your JavaScript into a single file, are as common as lazy engineers. Whichever mistake you manage to make, read on to find out the 12 most common WordPress mistakes that new and seasoned developers make.

Process-oriented programming is a paradigm in which the process structure and communication between processes of a system are the primary concerns. That’s the paradigm, but how does it work in real life?

Building a reactive web application is a lot more about how you handle events and data flow in your applications than the tools you use to do so. However, Angular 2 with Ngrx seems to be the perfect combination for building reactive applications for many reasons.

In this article, Toptal Freelance Software Engineer Simon Boissonneault-Robert walks you through a reactive web application tutorial using Angular and Ngrx and shows how these two technologies make it easy to do that.

Dropwizard allows developers to quickly bootstrap their projects and package applications as easily deployable standalone services. It also happens to be relatively simple to use and implement.

In this tutorial, Toptal Freelance Software Engineer Dusan Simonovic will introduce you to Dropwizard and demonstrate how you can use this powerful framework to create RESTful web services with ease.

Docker itself has been around for years and is composed of many inter-operating pieces. One of them is Docker Swarm, which allows you to declare your applications as stacks of services, and let Docker handle the rest.

In this article, Toptal Freelance Software Engineer Luke Sapan explains how to use Docker Swarm to deploy your own self-managing stack, followed by a quick example.

Spring Batch is a lightweight, comprehensive framework designed to facilitate the development of robust batch applications. It’s easy to set up, and even easier to use.

In this article, Toptal Freelance Software Engineer Alexey Saenko explains the programming model and the domain language of batch applications, using detailed code examples that should help any developer looking to get a head start in Spring Batch.

Video accounts for more than three quarters of all bandwidth used today. That’s why developers need a solid, extensible, and advanced media framework that doesn’t come with a steep learning curve.

In this tutorial, Toptal Freelance Software Engineer Raul Jimenez will introduce you to one such framework – Videogular. If you need to harness the power of Angular for HTML5 video, look no further.

There is no way around application diagnostics. No matter how good your code is, you will need to be able to monitor and study system behavior. This is where Android’s DDMS shines.

In this article, Senior Android Engineer Gilad Haimov explains how veteran Android developers leverage the potential of DDMS to improve app stability and performance, test new features, diagnose, and debug their code.

Why does a React web app run slow? The answer often lies in when and how frequently your components re-render, and whether those re-renders were even necessary. React doesn’t promise magical performance gains, but it provides just the right tools and functionalities to make it easy.

In this article, Toptal Freelance Software Engineer William Wang walks us through some optimization techniques that can help you build performant React web apps.

Social networks are among the biggest sources of data today, and this means they are an extremely valuable asset for marketers, big data specialists, and even individual users like journalists and other professionals. Harnessing the potential of real-time Twitter data is also useful in many time-sensitive business processes.

In this article, Toptal Freelance Software Engineer Hanee’ Medhat explains how you can build a simple Python application to leverage the power of Apache Spark, and then use it to read and process tweets to identify trending hashtags.

From virtual showrooms to elaborate research and testing scenarios, virtual reality is starting to make its mark on the automotive industry. It can be used to educate novice drivers, train professionals operating industrial equipment, or test vehicles and drivers in extreme conditions.

In this article, Toptal Freelance Software Engineer Daan Terra shares his experiences in the field of automotive simulations, explaining how VR can fundamentally change the way cars are marketed, tested, and developed.

Whether you just want to create an interactive 3D logo, on the screen or design a fully fledged game, knowing the principles of 3D graphics rendering will help you achieve your goal.

In this article, Toptal Freelance Software Engineer Adnan Ademovic gives us a step-by-step tutorial to rendering objects with textures and lighting, by breaking down abstract concepts like objects, lights, and cameras into simple WebGL procedures.

Understanding the Input/Output (I/O) model of your application can mean the difference between an application that deals with the load it is subjected to, and one that crumples in the face of real-world uses cases. Perhaps while your application is small and does not serve high loads, it may matter far less. But as your application’s traffic load increases, working with the wrong I/O model can get you into a world of hurt.

Compilation and linking are two very fundamental processes that happen all the time during C++ software development. However, what happens during these processes? How does the compiler go from your neatly organized source code to a binary file that the machine understands?

In this article, Toptal Freelance Software Engineer Daniel Trejo explains how a C++ compiler works with some of the basic language constructs to answer some common questions that are related to these processes.

Writing reusable code that can be shared across multiple platforms can make developing mobile applications a lot easier. But, how do you do that without paying the usual cost of maintainability, ease of testing, and poor user experience that comes with cross-platform mobile application development?

In this article, Toptal Freelance Software Engineer Emran Bajrami walks us through Xamarin and shows us techniques for building high-quality cross-platform apps.

Security has always been a primary concern for database experts, and with the advent of new, decentralized services, it’s become even more crucial. Microsoft addressed the need for an added level of security in SQL with the introduction of Always Encrypted functionality in SQL Server 2016.

In this blog post, Toptal Freelance Software Engineer Josip Saban explains how Microsoft’s Always Encrypted concept works, how it’s implemented, and why developers can’t afford to ignore it.

If there is something every front-end developer wants, it is proper support for variables in CSS. For years, to work around this missing feature, developers have resorted to CSS preprocessors. However, all that changes with the introduction of CSS custom properties.

In this article, Toptal Freelance Software Engineer Nicolás J. Engler walks us through CSS custom properties and shows us how they can be used to make better, more dynamic stylesheets.

Learn how, with the right remote worker security policy, distributed teams can be just as secure as in-house teams.

Toptal Freelance Software Engineer and full-time remote worker Amin Shah Gilani walks us through common security attack methods, cyber defense strategies, and, finally, an example of a good remote worker security policy.

In this tutorial, we will look at some common mistakes that are often made by Django developers and ways to avoid them. This tutorial is useful even if you’re a skilled Django developer because these mistakes aren’t just limited to new developers taking their first stab at Django.

Deploying new features with Salesforce can be problematic in more ways than one. It is crucial to have a sound strategy governing the publication of new releases, without running the risk of breaking your product.

In this post, Toptal Software Engineer Ajinkya Deshmukh will provide you with all relevant information and key tips that will allow you to manage your next Salesforce release smoothly.

Magento built a reputation as an e-commerce market leader, all thanks to its ease of use and customizability. Getting into the framework was only made easier with the release of Magento 2.

In this post, Toptal Software Engineer Gabriel Queiroz Silva gives us a step-by-step tutorial to building your first Magento 2 website.

Fat controllers and models: an inevitable problem for most large-scale projects based on MVC frameworks such as Yii and Laravel. Fortunately, there’s a cure, and it’s in architecting a layered structure.

Natural language is increasingly becoming a viable way of interacting with smart software. Google search, Apple’s Siri, Microsoft’s Cortana, etc. are all capable of understanding queries in natural language.

In this article, Toptal Freelance Software Engineer Shanglun (Sean) Wang walks us through some useful concepts and techniques in natural language processing and shows how they can be used to build a simple NLP app.

Many problems have optimal algorithms developed for them, while many others require us to randomly guess until we get a good answer. Even an optimal solution becomes slow and complex at a certain scale, at which point we can turn to natural processes to see how they reach acceptable results.

In this article, Toptal Freelance Software Engineer Eugene Ossipov walks us through the basics of creating a Genetic Algorithm and gives us the knowledge to delve deeper into solving any problems using this approach.

Although CSS was meant to deal with styling, creating extraordinary layouts on the web has always been a unique challenge and almost always required the developer to resort to JavaScript. However, Flexbox is here to change that.

In this article, Toptal Freelance Software Engineer Diego Díaz walks us through the basics of Flexbox and some cool examples of how Flexbox can be used to build smart CSS-only layouts.

Java’s open source Spring framework is a popular tool for creating high performing applications using plain old Java objects, but as with any tool, inappropriate use can lead to trouble. In this article, we cover the most common pitfalls of using the Spring framework so new and experienced developers alike have a roadmap of what to avoid.

Java has some idiosyncrasies of its own and design choices that can make it rather verbose. While Java is a mature and performant programming language, developers frequently need to write boilerplate code that bring little or no real value other than complying with some set of constraints and conventions.

In this article, Toptal Freelance Software Engineer Miguel García López shows how Project Lombok can help dramatically reduce the amount of boilerplate code that needs to be written in a Java application.

Android provides many ways of creating and managing threads, and third-party libraries exist to make that even easier. However, with so many options, choosing the right approach can be quite confusing.

In this article, Toptal Freelance Software Engineer Eliran Goshen discusses some common scenarios in Android development that involve threading and how each of the scenarios can be dealt with.

Using Mockito is not just a matter of adding another dependency. It requires changing how you think about your unit tests while removing a lot of boilerplate.

In this article, we’ll cover multiple mock interfaces, listening invocations, matchers, and argument captors, and see firsthand how Mockito makes your tests cleaner and easier to understand.

Developing a mobile app for multiple platforms can be quite costly. Implementing the same functionalities in multiple programming languages and dealing with a plethora of unique libraries for each platform requires a massive amount of time and knowledge.

In this article, Toptal Freelance Software Engineer Sylvain Gravel talks about Xamarin and its companion technologies that let you build mobile applications for multiple platforms without compromising familiarity, performance, and uniqueness.

Dealing with concurrency in Android through imperative-style programming can be quite the hassle. RxJava, a library for reactive and functional style programming, allows concurrency constructs to be modeled in a reactive way in Android’s non-reactive world.

In this article, Toptal Freelance Software Engineer Christopher Arriola shows us how RxJava can be incrementally introduced to existing Android projects and leveraged to simplify concurrency.

Many popular languages for web development have their ‘default’ framework, such as Ruby on Rails for Ruby, or Django for Python. However, PHP has no such single default and has multiple popular options to choose from.

In this article, Toptal Freelance Developer Karim Sakhibgareev compares the two most popular PHP frameworks, Symfony and Laravel, explores their features, and establishes guidelines for how PHP developers should choose between them.

Modern mobile application development requires a well thought-out plan for keeping user data in sync across various devices. This is a thorny problem with many gotchas and pitfalls, but users expect the feature and expect it to work well. For iOS and macOS, Apple provides a robust toolkit, called CloudKit API, which allows developers targeting Apple platforms to solve this synchronization problem.

In this article, Toptal Software Engineer Paul Young demonstrate how to use CloudKit to keep a user’s data in sync between multiple clients.

Automated software tests are critically important to the long-term quality, maintainability, and extensibility of software projects, and for Java, JUnit is the path to automation.

While most of this article will focus on writing robust unit tests and utilizing stubbing, mocking, and dependency injection, Toptal Software Engineer Josh Hayden will also discuss JUnit and integration tests.

For a while, WordPress seemed to had fallen behind. As the web became more reliant on JavaScript to create immersive, interactive experiences, it became increasingly clear that WordPress needed to offer new ways for users and developers to interact with its content.

In this post, Toptal Freelance Developer Brian Coords explores the amazing new features of WordPress’s REST API, showing why WordPress is still on the cutting edge of web development.

Whether you’re a bootstrapped startup that needs a brochureware website or a corporation that needs a high-performing web app, this post is for you. In it, Toptal Software Engineer Amin Shah Gilani teaches you how to setup a static, SSL-secure website for the very low cost of free, using Github Pages and Cloudflare.

Could you be using Git more efficiently?

The answer is probably a resounding “Yes,” which is why Toptal Software Engineer Ursula Clarke wrote today’s post.

In it, she teaches you how to use git stash, git reset, git bisect, git squash, and git rebase for maximum productivity.

So you’ve implemented user authentication. Now, you want to allow your users to log in with Twitter, Facebook or Google. No problem. You’re only a few lines of code away from doing so.

But while there are hundreds of OAuth 2 packages that pip knows, only a few actually do what they’re supposed to do.

In this article, Toptal Software Engineer Peter Goodspeed-Niklaus explains how to integrate OAuth 2 into your Django or Django Rest Framework using Python Social Auth.

In this tutorial, you will learn how automated testing works for the iOS platform and how to implement it in your project.

It’s every developer’s dream to be more efficient. In this article, you’ll learn how one engineer saved himself from typing more than 20,000 characters over six months and prevented 1,000 bugs in the process.

The Ionic project is rapidly gaining in popularity and is one of the most popular open source projects worldwide. With the recent announcement of the stable version of Ionic 2, this is the perfect time to underscore the Ionic 2 and its predecessor.

In this post, Toptal software engineer Julien Renaux outlines the major changes Ionic 2 brought to the platform and explains how to put these new features to good use.

In this article, Toptal Software Engineer Martin Gouws explains advanced features of the Node Package Manager that should be in every JavaScript developer’s knowledge base.

On every new project, you have the privilege of deciding how you’ll architect the app and organize the code. But if you don’t pay attention, or you rush through coding, you risk ending up with spaghetti code. The solution? Use a proper design pattern.

In this tutorial, Toptal Software Engineer Dino Bartošak explains how to implement an MVVM design pattern on a demo Swift application.

Freelancers work flexible hours, but this convenience comes at a price: They have to manage their time better than on-site professionals. However, it also means they’re free to optimize their routine and achieve exceptional efficiency.

In this post, software engineer Dmitry Ryazantsev will guide you through the ins and outs of personal time management, leaving little to chance. What good are great rates if you waste hours each week?

In back-end software development, increased productivity often comes at the cost of performance. In this article, Toptal Software Engineer Eduardo Bautista shows us how the Phoenix framework builds on the familiar concepts from the Rails world, and makes it even easier to build robust concurrent applications without compromising performance.

In an ever growing ecosystem of rich and complicated JavaScript applications, there’s more state to be managed than ever before: the current user, the list of posts loaded, etc.Managing state can be hard and error prone, but immutability and Redux- a predictable state container for JavaScript apps- can help significantly.

In this article, Toptal Programmer David Xu talks about managing state using immutability with Redux, a predictable state container.

The Webpack module bundler processes JavaScript code and all static assets, such as stylesheets, images, and fonts. However, configuring Webpack and its dependencies can be cumbersome and not always a straightforward process, especially for beginners.

In this article, Toptal Software Engineer Andrej Gajdos provides a guide with examples on how to configure Webpack for different scenarios and points out the most common pitfalls connected to project dependencies and their bundling when using Webpack.

Making your website or web app available to a wider audience often requires it to be available in multiple languages. For non-English projects, you can increase your audience by releasing it in English as well as your native language. Internationalizing and localizing your project, however, becomes a much easier process if you start during its infancy.

In this article, Toptal Software Engineer Igor Gomes dos Santos shows us how to leverage simple tools, like Gettext and Poedit, to internationalize and localize a PHP project.

Since the inception of the platform, Android developers have had pretty much only one option for a database: SQLite. Although feature-rich and powerful, it wasn’t quite what Android app developers needed. Realm, a modern, efficient database solution for mobile platforms, turned out to be an amazing replacement for SQLite on Android.

In this article, Toptal Software Engineer Mateus Gondim Romão Batista explains why you should use Realm for your next Android application.

PostCSS is the hot new tool that’s making the rounds on the front-end side of web development. It has been quickly and widely adopted, and possibly will have a significant impact on how we base our present-day CSS.

In this article, Toptal Software Engineer Nicolás J. Engler introduces us and guides us on how to start using this tool, expand it with plugins, or integrate with other CSS processors, task runners, or bundlers.

If you’ve spent your fair share of time developing web front-ends, you know that no amount of libraries and plugins are sufficient enough to make the development experience pleasant. Unpredictable event chains, complex data binding, and lack of structured data modeling only makes things worse.

Elm, a programming language built for front-end development, cuts to the root of all these problems and solves them there.

In this post, Toptal Software Engineer Stanislav Davydov provides a detailed guide to Elm and shows us how The Elm Architecture solves some of the most fundamental challenges of front-end development.

Software is regular and predictable, so it seems paradoxical that practically every web app needs a sizable administrative area. The explanation for this paradox lies in software’s interaction with humans. While you probably can’t build a fully automated system, there’s a lot you can do to save time and money.

In this post, Entrepreneur Jack Kinsella explains what you can do to streamline administration, thus saving valuable time and making your projects more profitable. Adminimisation is the word of the day!

Today, WordPress covers more than 50 percent of website shares and serves nearly 60 million websites worldwide. Its popularity has resulted in many misconceptions that have grown and spread like a forest fire, and have made people stay away from WordPress.

In this post, Toptal Software Engineer Donald Mudenge explains the five most common WordPress taboos and myths, clarifies them, and offers solutions on how to overcome them.

Your software isn’t fully tested until you write integration tests for it. While unit tests help ensure that functions are properly written, integration tests help ensure that the system is working properly as a whole.

In this article, Toptal Software Engineer Luka Blažecki uses Node.js to explain why integration testing is important for every development platform and how to write clean, composable integration tests.

WordPress plugins can be both a blessing and a curse. With more than 45,000 plugins available in its official repository, WordPress users can customize their website to their heart’s content. However, not all plugins follow the standards necessary to keep the platform performant and secure while also delivering a solid user experience.

In this tutorial, Toptal Software Engineer Ratko Solaja shows us how to build a robust WordPress plugin, following all the necessary best practices.

In the past few years, Microsoft has pulled a few aces from up its sleeve. Yes, they messed up Skype, failed with smartphones, and almost succeeded with tablets. But, they did some really amazing things as well.

Relinquishing their closed empire approach, they open-sourced .NET, joined the Linux Foundation, released SQL Server for Linux, and created this great new tool called Visual Studio for Mac.

In this post, Head of Open Source Demir Selmanovic details how to make an Android and iOS app in C# on your Mac.

Limited SQL scalability has prompted the industry to develop and deploy a number of NoSQL database management systems, with a focus on performance, reliability, and consistency. The trend was driven by proprietary NoSQL databases developed by Google and Amazon. Eventually, open-source systems like MongoDB, Cassandra, and Hypertable brought NoSQL within reach of everyone.

In this post, Senior Software Engineer Mohamad Altarade dives into some of them and explains why NoSQL will probably be with us for years to come.

WordPress, one of the most popular publishing platforms, has stood the test of time and now powers a significant portion of the web. Sadly, its reputation is plagued by claims of poor performance and complexity with scaling. However, the root causes of such performance issues are often bad code and poorly implemented plugins and themes.

In this post, Toptal Software Engineer Martín Di Felice shares tips and tricks for WordPress developers who want to build better plugins and themes and destroy the notion that WordPress is a slow platform.

Your website is gaining traction, and you are growing rapidly. Ruby/Rails is your programming language of choice. Your team is bigger and you’ve given up on “fat models, skinny controllers” as a design style for your Rails apps. However, you still don’t want to abandon using Rails? No problem.

In this article, Toptal Software Engineer Eqbal Quran explains how you can decouple and isolate your Rails components using nothing Plain Old Ruby Objects. Ruby objects and abstractions can decouple concerns, simplify testing, and help you produce clean, maintainable code.

With the rise of big data and data science, storage and retrieval have become a critical pipeline component for data use and analysis. Recently, new data storage technologies have emerged. But the question is: Which one should you choose? Which one is best suited for data engineering?

In this article, Toptal Data Scientist Ken Hu compares three prominent storage technologies within the context of data engineering.

Most modern programming languages, in the hopes of enhanced maintainability and reusability of code, offer some constructs that help the developer keep the definition of behavior and its implementation separate.

Swift takes the idea of interfaces a step further with protocols. With protocols and protocol extensions, Swift allows developers to enforce elaborate conformity rules without compromising the expressiveness of the language.

In this article, Toptal Software Engineer Alexander Gaidukov explores Swift protocols and how protocol-oriented programming can improve the maintainability and reusability of your code.

Let’s face it: Sometimes you just need to rant. Fortunately, there’s an app for that. It’s called devRant, and it’s the place for developers to vent about clients from hell, non-technical friends and family, and clueless recruiters.

In this roundup, devRant Co-Founder David Fox shares his favorite collection of rants since launching. Some will make you laugh. Others will make you laugh so hard you cry. And just about all of them will make you empathize with the author.

If you’re a veteran frontender, you’ve probably had some not-so-great experiences with designers, and chances are some designers have had an equally bad experience working with you. How can you make sure you get exactly what you need from your designer, without placing an undue burden on them?

It’s a tall order, but in this article Freelance Software Engineer Vedran Aberle Tokic outlines and addresses a number of potential issues that may become roadblocks for your execution. Implementing these suggestions may result in overhead for designers, but they can save enormous amounts of time and headache elsewhere.

Nobody wants to leave valuable customer data behind. Unfortunately, though, the hardest part of data migration to a complex CRM system, such as Salesforce, is the handling of legacy data.

In this article, Toptal Software Engineer Marian Paul provides 10 tips for successful legacy data migration to Salesforce.

Client-server interactions play a vital role in most modern mobile applications. By leveraging available backend services these mobile applications can provide some really amazing functionalities. However, as mobile applications grow complex it becomes essential to keep the networking module as clean and maintainable as possible - separated from the rest of the application logic.

In this article, Toptal freelance software engineer Alexander Gaidukov walks us through the design of a simple networking module that allows your iOS application to interact with RESTful APIs.

The Hadoop Distributed File System (HDFS) is a scalable, open source solution for storing and processing large volumes of data. With its built-in replication and resilience to disk failures, HDFS is an ideal system for storing and processing data for analytics.

In this step-by-step tutorial, Toptal Database Developer Dallas H. Snider details how to migrate existing data from a PostgreSQL database into the more efficient HDFS.

Genome data is one of the most widely analyzed datasets in the realm of Bioinformatics. The SciPy stack offers a suite of popular Python packages designed for numerical computing, data transformation, analysis and visualization, which is ideal for many bioinformatic analysis needs.

In this tutorial, Toptal Software Engineer Zhuyi Xue walks us through some of the capabilities of the SciPy stack. He also answers some interesting questions about the human genome, including: How much of the genome is incomplete? How long is a typical gene?

Swift is the new programming language created to be a modern replacement for Objective-C in iOS and OS X application development. In general, a skilled Swift developer is usually someone who is already experienced with Objective-C, and that, among other things, might lead them to write Swift code using Objective-C best practices, which can cause some bad mistakes.

In this article, Toptal Freelance Software Engineer Nilson Souto outlines the most common mistakes Swift developers should be aware of.

Any experienced developer will tell you that their best code isn’t code they wrote. It’s code they took from someone else’s work. Many of the problems we encounter have already been solved—and the remedies packaged into libraries available to anyone. Why reinvent the wheel when free wheels are everywhere?

In this guide, Senior Android Engineer Gilad Haimov will take you on a quick tour of some the most powerful Android libraries out there. Robust as a hammer, faster than a drill, and more precise than any scalpel; no Android developer should leave home without these must-have tools.

Google formally announced Android 7.0 a few weeks ago, but as usual, you’ll have to wait for it. Thanks to the Android update model, most users won’t get their Android 7.0 over-the-air (OTA) updates for months. However, this does not mean developers can afford to ignore Android Nougat.

In this article, Toptal Technical Editor Nermin Hajdarbegovic takes a closer look at Android 7.0, outlining new features and changes. While Android 7.0 is by no means revolutionary, the introduction of a new graphics API, a new JIT compiler, and a range of UI and performance tweaks will undoubtedly unlock more potential and generate a few new possibilities.

Apple’s iOS is the second-largest mobile operating system in the world. It also has a very high adoption rate, with more than 85 percent of users on the latest version. These highly engaged users have high expectations: If your app has bugs, you’ll hear about it. And once the one-star reviews start rolling in, it’s hard to recover.

In this article, Toptal Software Engineer Nikita Tuk outlines the 10 most common mistakes that developers make—and how to avoid them.

Gone are the days where front-end developers for web applications could use ad-hoc JavaScript with jQuery and such all in a single JavaScript file. Modern web applications require more effort from the developer to adopt an overall architecture and development process. Building such front-end applications relies on lots of external dependencies and modular source code, and these elements necessitate automation to save developers time and reduce the chances of mistakes.

In this article, Toptal Freelance Software Engineer Eric Grosse shows us how various combinations of the popular tools Webpack, Browserify, Gulp and Npm can benefit us by enhancing our development environment and allowing us to focus on writing the app itself.

Caching is a powerful technique for increasing performance, but the whole idea behind caching works only as long as the result we cached remains valid. And here we get to the hard part of the problem: How do we determine when a cached item has become invalid and needs to be recreated?

In this article, Toptal Freelance Software Engineer Daniel Ivanov provides an ASP.NET-based solution to replace invalid cached items and assure high throughput and performance of web applications designed to handle a high load.

In the realm of software development, time and date manipulation is considered by many to be a difficult task. Complicated time zone rules, leap seconds, differences in locale-specific formatting, etc., force us to immediately resort to popular time and date manipulation libraries. We often use these libraries without thinking about how exactly they work, which can lead to all sorts of obscure bugs in our software.

In this article, Toptal Freelance Software Engineer Punit Jajodia gives us an in-depth introduction to some concepts and best practices to avoid a few of the obvious issues related to changing the time and date in our applications.

Are you building the next big thing? Planning to become the next Facebook or Google? Are you at the point of making fundamental decisions that will stay with you for the entire project? There is a good chance that you will pick a robust language like Java. If so, you want to pick the best object-oriented abstraction of your flexible data model because you don’t want to deal with plain SQL. You want to support all kinds of data and ideally, support all kind of databases. If so, there’s is only one right choice for you: Hibernate.

Continue reading the story written by Freelance Software Engineer Grzegorz Gajos, about one of these imaginary but entirely possible scenarios.

The rise of the web and mobile applications has led to an increased need for back-end API services. Ruby on Rails’ philosophy seemingly makes it the ideal framework for creating back-end APIs. However, using Rails only for the API is overkill.

In this article, Freelance Software Engineer Boško Ivanišević explores alternatives to Rails and introduces us to two very mature and powerful gems, Sinatra and Sequel, which in combination provide powerful tools for creating server-side APIs.

WordPress is easily the most powerful open source blogging and content management system available online today. As WordPress is easy enough to set up and has a user-friendly approach, many developers are often underestimating it and so make mistakes in development.

In this article, Toptal Freelance Software Engineer Andrew Schultz outlines the ten most common mistakes that WordPress developers should be aware of for future projects.

How do you define good code? Is it 100% test coverage, or is it backwards compatibility with decade-old hardware? We may not be able to reach an end to this debate yet, but good software always seems to conform to a few certain qualities of code.

In this article, Toptal Freelance Software Engineer Zachary Goldberg walks us through six simple ideas that can help you make better, more maintainable software.

Implementing applications that deal with complex concurrent behavior has always been a challenging aspect of programming. Various paradigms exist that promise a solution to this problem in different ways. RxJava is a Java library that enables Functional Reactive Programming in Android development. It raises the level of abstraction around threading in order to simplify the implementation of complex concurrent behavior.

In this article, Toptal Freelance Software Engineer Christopher Arriola gives us a detailed walkthrough of RxJava and how it fits into the realm of Android development.

Linux is now 25 years old, but it’s no hipster. It’s not chasing around Pokemon, and it’s not moving back in with its parents due to crippling student debt. In fact, Linux is still growing and evolving, but the core ideas of the Linux State of Mind remain the same.

In this article, Toptal Technical Editor Nermin Hajdarbegovic takes a look at the history of Linux development, the state of Linux today, and what’s next for the world’s most popular open-source operating system.

Kotlin is a new, expressive general-purpose programming language powered by the same virtual machine technology that powers Java. Since Kotlin compiles to the JVM bytecode, it can be used side-by-side with Java, and it does not come with a performance overhead.

In this article, Toptal Freelance Software Engineer Ivan Kušt gives us a walkthrough of ten major features of Kotlin that help avoid boilerplate code and, more importantly, save time.

More than two decades ago, Java shook the world with its “Write once, run anywhere“ slogan. Today, Java developers have at their disposal a whole set of tools, such as Spring Boot, Docker, Cloud, Amazon Web Services, and Continuous Delivery, to take development and delivery to a whole new universe.

In this article, Toptal Freelance Software Engineer Matko Šuflaj presents all these technologies and guides us through a step-by-step tutorial on how to build a small microservice and prepare it for continuous integration in the cloud.

As a result of smartphones and mobile applications becoming so popular, web developers have been looking for ways to create mobile applications using JavaScript. This increased demand has led to the development of many JavaScript frameworks capable of running native-like applications on mobile devices.

In this article, Toptal Freelance Software Engineer Johannes Stein compares the current two most popular choices for mobile-oriented JavaScript frameworks, Cordova and React Native. Examining their advantages and pitfalls, he dives into details of each and compares them across different disciplines.

What’s the biggest problem with crowdfunding today? Everyone wants a sweet slice of the crowdfunded pie, but nobody wants a single crumb of responsibility. As a result, crowdfunding platforms, the tech press, and the geek public have picked up a track record filled with spectacular crowdfunding failures.

In this article, Toptal Technical Editor Nermin Hajdarbegovic takes a look at the state of crowdfunding today and explains why the industry needs to do more to clean up its act and get rid of bad apples in crowdfunding.

Java may have stood the test of time, but it can still be a source of great frustration among many web developers. Dealing with its verbosity and infrastructure overhead, for example, can take hours, even for the most basic needs.

In this article, Toptal Freelance Software Engineer Gregor Ambrozic shows us how Grails and its many appealing features can be a viable alternative to traditional Java web applications frameworks.

Elixir, with its simple and clean syntax, makes building scalable and maintainable concurrent applications a breeze. Ecto is a database wrapper that lives up to the high expectations set by Elixir’s reputation. Its domain-specific language provides a pleasant way to interact with databases and build fault-tolerant, concurrent applications in Elixir with ease.

In this article, Toptal Freelance Software Engineer Boris Barroso walks us through Ecto and its four main components: Repo, Schema, Changeset and Query.

Social networks are a rich source of user information. From a person’s current mood to endless streams of photos, there is by now probably a social network for each aspect of human life. From the development side, access to users’ information can be an essential element in providing a truly personalized experience in any application.

In this article, Toptal Freelance Software Engineer Behsaad Ramez shows us how the APIs of some of these social networks stack against each other and how they may be leveraged to accumulate precious information about users.

In today’s world, code is expected to change as quickly as requirements do, and tests play an important role in making that possible. Many modern projects boast great test coverage, making them more resilient to regression issues. However, that is not true for all projects - especially some legacy projects which have little in the way of testing.

In this article, Toptal Freelance Software Engineer Andrey Shalitkin discusses two metrics, coupling and cyclomatic complexity, that are important in identifying which portions of code to include in test coverage.

In the realm of enterprise software, especially for software provided as a service, multitenancy ensures that data is truly isolated for each client within a shared instance of software. Among its numerous benefits, multitenancy can greatly simplify release management and cut down costs.

In this article, Toptal Freelance Software Engineer André William Prade Hildinger shows us how Hibernate, a persistence framework for Java, makes implementing a multitenant Java EE application easier than it sounds.

Of all the modern ways people talk to each other, email seems to have stood the test of time and is arguably still one of the most effective and widely used means of communication. Thus, being able to programmatically send and receive emails can open new dimensions to a user’s experience of software that powers human communication.

In this article, Toptal Freelance Software Engineer Francis Altomare shows us how he leveraged various Amazon Web Services technologies to build a simple communication application in which email itself is an important interface.

You can buy capri pants, cheap flip-flops, and boonie hats anywhere on vacation, but beachside shops usually don’t carry quality hardware that can help you be more productive on the road or save you time and money for more enjoyable activities.

In this post, Toptal Technical Editor Nermin Hajdarbegovic takes a look at inexpensive and readily available travel hardware designed to boost your productivity on the road. You can put most of these gadgets on your summer shopping list without making a dent in your travel budget.

Memory issues in programs can be quite frustrating whether you’re the user or the developer attempting to solve the problem. In Ruby, the garbage collector plays a vital role in managing your program’s memory so that you can focus on other important things. However, it is often possible to overwhelm the garbage collector or end up with sneaky resources that cannot be freed, which can lead to all sorts of memory issues.

In this article, Toptal Freelance Software Engineer Bruz Marzolf explains why certain memory issues arise in Ruby applications and how to tackle them easily.

Java has been a dominant programming language for ages, but modern times call for modern languages. Meet Kotlin, a modern, clear, and expressive programming language powered by the same virtual machine technology that powers Java.

In this article, Toptal Freelance Software Engineer Tomasz Czura takes us for a spin through the world of Kotlin and shows us how it can be used to make an Android application with an elegant architecture without compromising the very qualities of the code that Kotlin aims to provide.

The plethora of tutorials on building Android apps may have you thinking that making a mobile app is simple. In reality, however, performance issues can be very complicated, and because performance plays a key role in making sure that your app stays on your users’ list of favorite apps for a long time, every little detail must be given one’s full attention.

In this article, Toptal Freelance Software Engineer Tibor Kaputa shares some tips on how you can optimize some common performance issues and identify some of the bottlenecks in your Android app.

When Golang first came out, there were next to no resources available about how to efficiently test your Go-written application. Even now, with plenty of guides and recommendations available, many bright-eyed developers still try to apply their Ruby or JavaScript mindset and use external frameworks to test apps written in Go.

In this article, Toptal Freelance Developer Gabriel Aszalos first explains Golang philosophy and then covers the basics of testing in Go, from table testing to JSON response assertion.

Are you a Scala developer hoping to scale your application in the cloud? If so, meet Kubernetes, a cluster manager for Docker applications. Developed by Google, it’s the latest in new open source tools making major waves.

In this article, Toptal Freelance Software Engineer Michele Sciabarra guides us through a step-by-step tutorial on how to take a generic Scala application and implement Kubernetes and Docker to launch multiple instances of the application.

When dealing with web-based projects that run in the production environment, being able to build and deploy changes quickly is a top priority. However, repetitive processes such as building front-end assets, when not automated, can be prone to critical errors.

In this article, Toptal Freelance Software Engineer Anton Kanevsky shows us how Gulp can solve various challenges of build automation through simple JavaScript routines.

As a language, R is strongly tied to data and is thus used mostly by statisticians and data scientists. Many who already use R for machine learning, though, are not aware that data munging can be done faster in R, meaning another tool is not required for that task.

In this article, Freelance Software Engineer Jan Gorecki explores tabular data transformations and introduces us to one of the fastest open-source data wrangling tools available.

“So much of what’s new and exciting about Angular 2 is its new way of thinking rather than its new architecture,” says Toptal Freelance Developer Ethan James.

In this article, Ethan walks through the inner workings of a simple Angular 1.5 app and then shows us how to upgrade it to Angular 2 while giving us the necessary understanding to truly appreciate it.

Meet Web Audio API, a powerful programming interface for controlling audio on the web. Gone are the days when the web browser could rarely play a sound file correctly. With this API, you can now load sound from different sources, apply effects, create visualizations, and do much more.

In this article, Toptal Freelance Software Engineer Joaquín Aldunate shows us how to unleash our inner musician using Web Audio API with the Tone.js framework by giving us a brief overview of what this API has to offer and how it can be used to manipulate audio on the web.

How many times have you used the find-and-replace functionality (or RegEx) across a directory to make changes to JavaScript source files? Up your refactoring game by using codemods, scripts used to rewrite other scripts.

In this article, Toptal Freelance Developer Jeremy Greer walks us through three common uses of codemods, using the toolkit “jscodeshift”.

The Scala language has continued to gain popularity over the last several years, thanks to its excellent combination of functional and object-oriented software development principles, and its implementation on top of the proven Java Virtual Machine (JVM).

Creating a language that compiles to Java bytecode requires a deep understanding of the inner workings of the Java Virtual Machine. To appreciate what Scala’s developers have accomplished, it is necessary to go under the hood, and explore how Scala’s source code is interpreted by the compiler to produce efficient and effective JVM bytecode.

More than 60 percent of trading activities with different assets rely on automated trading and machine learning instead of human traders. Today, specialized programs based on particular algorithms and learned patterns automatically buy and sell assets in various markets, with a goal to achieve a positive return in the long run.

In this article, Toptal Freelance Data Scientist Andrea Nalon explains how to predict, using machine learning and Python, which trade should be made next on the S&P 500 to get a positive gain.

Nowadays, front-end development workflows involve many modern tools and preprocessors that not only streamline the whole process, but also allow you to spend less time on common web tasks, giving you more time to focus on other aspects of the project that require more careful and skilled insight. Sass, the scripting language for syntactically awesome stylesheets, comes with robust and built-in support for mixins - an essential feature for keeping your stylesheets DRY.

In this article, Toptal Freelance Software Engineer Justin Brazeau shows us 10 useful Sass mixins that help keep your stylesheets manageable by breaking them into smaller reusable bits, each with its own focus.

Would you like to test your PHP code like a boss? Do you feel that basic unit tests and PHPUnit just don’t cut it anymore? If your answer to both questions is yes, you might want to try Codeception, a mature and well-documented testing framework designed to outperform PHPUnit and Behat.

In this post, Toptal Freelance Software Engineer Vasily Koval describes how he came to take the plunge and start using Codeception, and he explains why you should check out Codeception for your PHP testing needs.

Unity is an excellent and straightforward tool to use for multi-platform development. Its principles are easy to understand, so programmers can start developing new products quickly and intuitively. However, if developers do not keep some important things in mind, development can slow down at crucial points, including when the project moves away from initial prototype or is approaching final release.

In this article, Toptal Freelance Software Engineer Tomas Macek outlines the most common mistakes that Unity developers should be aware of for future projects.

Clustering algorithms are very important to unsupervised learning and are key elements of machine learning in general. These algorithms give meaning to data that are not labelled and help find structure in chaos. But not all clustering algorithms are created equal; each has its own pros and cons.

In this article, Toptal Freelance Software Engineer Lovro Iliassich explores a heap of clustering algorithms, from the well known K-Means algorithm to the elegant, state-of-the-art Affinity Propagation technique.

Software engineers are always searching for the best tools and guides to help them be more productive and allow them to spend less time reading long technical specifications.

Today, Toptal is pleased to present a new resource to the community: the JavaScript Cheat Sheet - ES6 and Beyond. Toptal’s JavaScript Cheat Sheet is a quick, easily understandable reference guide. It is free to download and includes all the new and exciting features introduced with ES6 as well as the future experimental features from ES7.

It’s tragically common for developers to come into a project where proper automated testing has been and will continue to be overlooked. It’s a situation Freelance Developer Bhushan Lodha has found himself in all too often; fortunately, he’s found a solution. In this article, he briefly covers the reasons why testing is overlooked and ultimately explains his “coding life hack” to ensure quality control even when he can’t introduce a testing framework.

Some platforms have an overwhelming number of options for web frameworks. Node.js, the event-driven server-side JavaScript environment, is one such platform. Whether it’s the minimalist Express or the full-blown MVC web framework Sails.js, Node.js seems to have it all.

In this article, Toptal Freelance Software Engineer Chuoxian Yang explores four of the most popular Node.js web frameworks and discusses how each framework stands out from the rest of the crowd in Node.js.

In a nutshell, declarative programming consists of instructing a program on what needs to be done, instead of telling it how to do it. This approach involves providing a domain-specific language (DSL) for expressing what the user wants. This DSL shields users from messy low-level constructs while still achieving the desired end-state.

While declarative programming offers advantages over the imperative approach it replaces, it’s not as straightforward as it may seem. In this comprehensive article, Toptal Freelance Software Engineer Federico Pereiro outlines his experience with declarative tools and explains how you can make declarative programming work for you.

Today, writing applications in languages that compile to JavaScript is a very common practice. Scala developers, for example, can use Scala.js and have the same language for both the server and the client. That said, Scala’s compiler and standard dependency management tools are too limiting in the modern JavaScript world.

In this article, Toptal Freelance Software Engineer Michele Sciabarra shows us how to integrate Scala.js with the plethora of JavaScript modules available on NPM, using tools like Browserify, and explains how to do this without even having to install Node.js.

Concurrency allows programs to deal with a lot of tasks at once. But writing concurrent programs isn’t a particularly easy feat. Dealing with constructs such as threads and locks and avoiding issues like race conditions and deadlocks can be quite cumbersome, making concurrent programs difficult to write.

In this article, Toptal Freelance Software Engineer Marko Dvečko gives us an overview of some concurrent programming models. He explains how each of these models gives structure to the programs we write and shows how to avoid certain concurrency issues that can come with these models.

Node-RED, built on Node.js, is a tool designed for programming visually without having to write any code. It comes equipped with a browser-based flow editor that allows hardware devices and APIs to be connected with each other easily, making it an ideal tool for rapidly developing programs for IoT devices.

In this article, Toptal freelance software engineer Jesús Darío Rivera walks us through the process of building a simple program using Node-RED and Netbeast along with a virtual light bulb plugin that mimics the capabilities of a real smart bulb.

When building smaller websites, the way developers structure their CSS code is usually not a big issue. However, when it comes to larger, more complex projects, code organization becomes crucial.

In this article, Toptal Freelance Software Engineer Tomislav Matijević introduces us to BEM methodology and explains how this CSS practice can massively improve code maintainability, speed up the development process, and streamline the teamwork of developers by arranging CSS classes into independent modules.

Streams are a powerful construct in Node.js and in I/O driven programming in general. Gulp, a tool for task automation, leverages streams in elegant ways to allow developers to enhance their build workflow.

In this article, Toptal engineer Mikhail Angelov gives us some insight into how Gulp works with streams by showing us step-by-step how to build a Gulp-like build automation tool.

Exceptions are as old as programming itself. An unhandled exception may cause unexpected behavior, and results can be spectacular. Over time, these errors have contributed to the impression that exceptions are bad.

But exceptions are a fundamental element of modern programming. Rather than fearing exceptions, we should embrace them and learn how to benefit from them. In this article, we will discuss how to manage exceptions elegantly, and use them to write clean code that is more maintainable.

HSA is a set of standards and specifications designed to allow further integration of CPUs and GPUs on the same bus. This is not an entirely new concept, but HSA takes it to the next level. HSA would effectively take the developer out of the equation, at least when it comes to assigning different loads to different processing cores.

In this post, Toptal Technical Editor and resident chip geek Nermin Hajdarbegovic takes a closer look at HSA and the future of heterogeneous computing in general. Get ready for some good news, but don’t forget to brace for bad news first.

Elixir, a dynamic, functional programming language, is designed for building scalable and maintainable applications with a simple, modern, and tidy syntax. Although it is easy to understand, Elixir’s approach to concurrency and its data type nuances require some getting used to.

In this article, Toptal engineer Kleber Virgilio Correia gives us a comprehensive guide to the various basic data types in that are available in Elixir.

As software engineers, we’re always searching for the best tools and guides that will help us to be more productive while spending less time searching and reading long technical specifications.

Today, Toptal is pleased to present an entirely new resource to the community as a free download: a CSS Cheat Sheet. Toptal’s CSS Cheat Sheet is a quick CSS reference guide, and includes CSS syntax, the most important selectors, properties, sizes, and units, and other useful CSS details, all in a short, easily understandable format.

How does one secure a vast, distributed network of tech talent? There are three ways of doing this: the right way, the wrong way, and the Toptal way. Today, we will be discussing the latter, and unveiling our plans for a comprehensive overhaul of our onboarding and authentication procedures.

In this post, Toptal Technical Editor Nermin Hajdarbegovic will help you get acquainted with our brand new processes. Since all Toptalers will be required to use our new security platform, we encourage you to comment and contribute to our efforts.

Camera systems are very important in conveying the right atmosphere in video games. When developing games, even 2D ones, advanced cameras should be your tool of choice.

In this article, Toptal engineer Mihai Cozma shows us how to build a modular camera system for 2D platform games using some simple components in Unity that can be easily extended to 2.5D or even 3D games.

Ionic is extremely popular at the moment, and it has revolutionized the hybrid application industry in a way that nobody could have imagined. However, over time, the best practices and tooling for Ionic have not progressed in the same way. As a result, the number of pitfalls that developers need to look out for when working with Ionic is still high.

In this article, Toptal Freelance Software Engineer Julien Renaux outlines the most common mistakes that Ionic developers should know.

The threaded model and global interpreter lock has always been in the way of Python handling thousands of concurrent long-lived connections. Modern web frameworks, such as Tornado, use non-blocking network I/O to make Python feasible for implementing WebSocket servers.

In this article, Toptal engineer Jongwook Kim walks us through the process of implementing a simple WebSocket-based web application in Python using the Tornado web framework.

When dealing with data analysis, most companies rely on MS Excel or Google Sheets, but dealing with data presented this way isn’t very eye-catching or intuitive. It’s once you add visualizations to this data that things become a little easier to manage. That’s the topic of today’s tutorial by our guest author from Adobe, Rohit Boggarapu. Join us as he guides us though the process of making interactive drill-down charts using jQuery and FusionCharts.

In the rapidly evolving Internet world, getting things done fast is always critical. Still, developers today waste hundreds of hours on tasks not related to programming: setting up databases or caches, deploying projects, monitoring online statistics, and so on.

In this article, Toptal Freelance Software Engineer Minhao Zhang guides us in a step-by-step tutorial on how to reduce waste by setting up your first virtual machine using Amazon Web Services, and introduces the most widely used AWS services that can boost your productivity in minutes.

Writing code that is easily testable takes some effort and planning. However, some patterns exist that can be used to write simple and functional code, making it easier to test them when the time comes.

In this article, Toptal engineer Joshua Mock shares some useful tips and patterns for writing testable code in JavaScript that are both simple to understand and simple to implement.

Navigation in mobile applications, when done right, can have tremendous positive impact on overall user experience. Android offers application developers multiple ways of implementing navigation in their application. However, not all navigation patterns are created equal.

In this article, Toptal engineer Becze Szabolcs shows us how to implement fragment-based navigation and how it stacks up against Android’s traditional navigation philosophy.

To create a .NET project from scratch, simply using Visual Studio Wizard is good enough most of the time. However, the default project settings produced by wizards are hardly acceptable for professional teams, as they set too low of a bar on quality.

In this article, Toptal Freelance Software Engineer Andrei Smirnov guides us through several standard practices, configuration files, and project settings every developer should apply when starting a new .NET project. Doing this in the very beginning of a project decreases future technical debt and makes product source code readable and professional-looking.

If you haven’t been working with PHP lately, you might wonder what happened to PHP 6. Why the skip from PHP 5 to PHP 7? Well, long story short, PHP 6 was a failure. To avoid confusion, the new version was renamed PHP 7.

PHP 7 introduces a number of new features, while at the same time dropping depreciated SAPIs and extensions. As a result, it tends to outperform PHP 5.x by a wide margin. Some compatibility issues could pose a problem, but most developers have nothing to worry about.

In this post, Toptal Freelance Software Engineer Vilson Duka explains what makes PHP 7 different, and why it’s time to make the switch.

Since its debut in 2008, Python 3 has come a long way. Gone are the days when it lacked support for almost all useful libraries and tools. Python 3 offers many improvements and amazing new features that make writing robust code in Python easier than ever.

In this article, Toptal engineer Dario Bertini discusses some of the improvements and features that Python 3 has to offer, and explains whether switching to Python 3 is a smart choice right now.

Meteor is a framework for rapidly building real-time JavaScript web applications. It can be used to build complex applications with amazing ease. However, that can often result in adoption of bad development practices and poorly structured code.

In this article, Toptal engineer Darion Cassel shares some simple ways to improve the structure of your next Meteor-based web application without resorting to complicated boilerplates and scaffolding tools.

Robot Operating System, a framework for building robot applications, allows developers to assemble a complex system by connecting existing solutions for small problems.

In this article, Toptal engineer Adnan Ademovic gives us a step-by-step tutorial to building software for an onboard computer that allows us to remotely control and monitor a robot and running it in a simulated world using Robot OS.

The current trend in graphic design is to use a lot of rounded corners in all sorts of shapes. We can observe this on many web pages, mobile devices, and desktop applications, as rounded corners make the user interface feel smoother and nicer. However, what if we have to generate rounded corners on the fly, and we cannot preload it from an image?

In this article, Toptal Freelance Software Engineer Bojan Kverh guides us in a step-by-step tutorial on how to develop a simple class in C++ that can turn a complex polygon into a shape with rounded corners using Bezier curves and QPainter.

AWS Lambda offers a relatively thin service with a rich set of ancillary configuration options, making it possible to implement easily scalable and maintainable applications leveraging these services.

In this article, Toptal engineer Andrew Crosio gives us a step-by-step tutorial for building an image uploading and resizing service and demonstrates how AWS Lambda can be used as a platform to easily build service oriented architecture applications.

Modern web browsers offer a number of different APIs and mechanisms to storing data on the client-side. But are all of these options created equal?

In this article, Toptal engineer Stephen Villee demystifies the various client-side storage options available in modern web browsers and explains how each of these can play a role in storing session data on the client-side.

With Microsoft’s no-brainer shift towards open source and interoperability it was only a matter of time before we started seeing alternatives to some of their key products, like Visual Studio. Enter Project Rider: the code name for IDE guru JetBrains’ competition to Visual Studio.

Here’s the lowdown on Project Rider, the newest member of the IntelliJ platform family.

The Art of War is an ancient military treatise, but despite its age, the text is still included in the syllabus at many military schools. Sun Tzu’s principles and teachings also have practical applications in politics, business, sports, and, believe it or not, software development. In fact, you might just be applying some of these principles in your daily routine, without even knowing.

In this post, Toptal Freelance Software Engineer Jose F. Maldonado explains why many of these ancient teachings still matter, and what you can do to make them work for you and your team.

Unlike most front-end web frameworks, React’s aim is to solve the various challenges of building user interfaces that rely on changing data. Although React is a simple JavaScript library and is easy to get started with, it is still possible to misuse it in ways that deny the web app from reaping the benefits that React has to offer.

In this article, Toptal engineer Ivan Rogic demonstrates the synergy of React, Redux and Immutable.js, and shows how these libraries together can solve many performance issues that are often encountered in large web applications.

Python is a powerful, object-based, high-level programming language with dynamic typing and binding. Due to its flexibility and power, developers often employ certain rules, or Python design patterns. What makes them so important and what do does this mean for the average Python developer?

In this post, Toptal Senior Software Engineer Andrei Boyanov explains why Python is great for design patterns, and how they can be used to unlock even more potential, or to streamline development and make code more maintainable.

Today, a massive amount of data is available in the form of networks or graphs. For example, the World Wide Web, with its web pages and hyperlinks, social networks, semantic networks, biological networks, citation networks for scientific literature, and so on.

A tree is a special type of graph, and is naturally suited to represent many types of data. The analysis of trees is an important field in computer and data science. In this article, we will look at the analysis of the link structure in trees. In particular, we will focus on tree kernels, a method for comparing tree graphs to each other, allowing us to get quantifiable measurements of their similarities or differences. This an important process for many modern applications such as classification and data analysis.

Microservices are one of the latest trends in software design. In a microservices architecture, the classic monolithic back-end is substituted by a suite of distributed services. This design allows better separation of responsibilities, easier maintenance, greater flexibility in the choice of technologies for each service, and easier scalability and fault tolerance.

In this article, Toptal Freelance Software Engineer Francisco Temudo guides us in a step-by-step tutorial on how to build a microservices suite using Ruby.

Hackathons often inspire engineers to create amazing software. By blending various technologies together, really useful and often fun projects can be realized in a short period of time.

In this article, Toptal engineer Radek Ostrowski shares his experience participating in the IBM Sparkathon, and walks us through how he elegantly combined the power of Apache Spark and Docker in IBM Bluemix to build a weather app.

With approximately one billion people using Microsoft Office, the DOCX format is the most popular de facto standard for exchanging document files between offices.

While DOCX is a complex format, you may want to parse it manually for simpler tasks such as indexing, converting to TXT and making other small modifications. I’d like to give you enough information on DOCX internals so you don’t have to reference the ECMA specifications, a massive 5,000 page manual.

More and more people are moving their work from desktop applications to the cloud using an equivalent online web application. However, this has unfortunately not been true for software development IDEs. Although there have been some attempts to provide an online IDE, they have not come anywhere close to traditional IDEs.

In this article, Toptal Freelance Software Engineer Michele Sciabarra guides us on how to build a cloud-based development environment for Scala and big data applications, with the help of Docker in Amazon AWS.

Although database programming does not evolve at nearly the same pace as traditional application programming, recent advancements in several fields are bringing new techniques and technologies within the reach of small and independent developers.

In this guide, Toptal Freelance Software Engineer Jeffrey Shumaker explains how developers can quickly and easily tap these methods to identify database issues they may not even be aware of, and how they can build excellent data mining tools without spending a lot on expensive software licenses.

Manual memory management is a nightmare that programmers have been inventing ways to avoid since the invention of the compiler. Programming languages with garbage collectors make life easier, but at the cost of performance.

In this article, Toptal engineer Peter Goodspeed-Niklaus gives us a peek into the history of garbage collectors and explains how notions of ownership and borrowing can help eliminate garbage collectors without compromising their safety guarantees.

EhCache is a widely-used, pure Java cache that can be easily integrated with most popular Java frameworks, such as Spring and Hibernate. It is often considered to be the most convenient choice for Java applications since it can be integrated into projects easily. EhCache Spring Annotations allows seamless integration into any Spring application by simply adding annotations to cacheable methods, without modifying the method implementations. This article focuses on boosting your Spring applications with EhCache Spring Annotations.

Google Cardboard was envisioned as the cheapest Virtual Reality (VR) solution on the planet, and at this point, nothing else comes close in terms of pricing. However, the low price did not bring about mass adoption, and Google’s Android-based VR platform is nothing more than a tech curiosity at this point.

In this post, Toptal Technical Editor Nermin Hajdarbegovic leverages his extensive experience in the graphics industry to explain what’s keeping Cardboard VR down, and what the platform needs to attract more users, investment, and development.

Java Virtual Machine (JVM), the powerful virtual machine behind programming languages like Java and Scala, provides a platform-independent environment for executing compiled bytecode. Programming languages built for the JVM can be used to write programs that can run on a wide range of platforms without modification and can even leverage all the libraries and frameworks that exist for the JVM.

In this article, Toptal engineer Federico Tomassetti presents an overview of the strategy and various tools involved in creating our very own programming language for the JVM.

Nowadays, almost all Python frameworks use WSGI as a means, if not the only means, to communicate with their web servers. This is how Django, Flask and many other popular frameworks do it.

This article intends to provide the reader with a glimpse into how WSGI works, and allow the reader to build a simple WSGI application or server.

The Dependency Injection Container in Symfony2 allows components to be injected with their dependencies, and is often used as a Service Locator, which when combined with the DI-container pattern is considered to be an anti-pattern by many.

In this article, Toptal engineer Vasilii Lapin shows us how you can build a simple Symfony2 application using the DI-container, but without implementing the Service Locator pattern.

Handling all validation in domain objects results in objects that are huge and complex to work with. In domain-driven design, using decoupled validator components allows your code to be much more reusable and enables validation rules to rapidly grow.

In this article, Toptal engineer Josip Medic shows us how validation can be decoupled from domain objects, made context-specific, and structured well to achieve more sustainable validation code.

Are we really going to need $500 phones to get people in developing countries on 3G or 4G? Not really.

Welcome to the world of commoditised smartphones. Allow us to explain what’s going on and why it could have a significant impact on software and hardware industries.

In this tutorial, Toptal Engineer Orban Botond demonstrates how to use the Grape gem – a REST-like API micro-framework for Ruby – to build backend support in Rails for a JSON API. Grape is designed to run as a mountable rack engine that complements your web applications without interfering with them.

CoffeeScript allows developers to make the most out of JavaScript-based platforms without having to jump through its awkward language hoops. However, with the introduction of ES6 features into major JavaScript engines, plain JavaScript is now nearly as friendly and powerful out-of-the-box as CoffeeScript.

In this article, Toptal engineer William Coates shares his findings on ES6 from the perspective of a CoffeeScript convert.

An operating system written in Node.js? Yes, it exists, and it’s called NodeOS. Think for a second about the progress Node.js has made in the short time it’s been around. Now, imagine the same thing happening with an operating system.

In this article, Toptal engineer Danny Morabito introduces us to NodeOS, guiding us with a step-by-step tutorial on how to create our first NodeOS application using nothing more than Node.js.

Smooth animations and flawless transitions are key to perceived performance in modern mobile applications. Without the right tools, tuning iOS animation for efficiency can be a challenge in itself.

In this article, Toptal engineer Stefan Progovac demonstrates the role of Instruments, a sophisticated set of performance profiling tools for iOS, discussing how they can help you understand animation performance bottlenecks and some strategies for working around them.

Processing makes prototyping visual apps a breeze. With its easy to use programming constructs and some mathematics, building a simple game is a lot easier than one may think.

In this article, Toptal engineer Oguz Gelal provides a step-by-step tutorial to building a game using Processing and porting it to the web.

Talking about proximity marketing will get you varying reactions, from concerns about privacy issues to the idea that your phone is going to spam you with annoying ads non-stop, but if you boil down the idea, there are some really compelling concepts here.

When you clear away all the buzzwords, what exactly is this shift we’re seeing? It’s the world customizing itself to you. The world is reacting to your presence, specific to you as an individual. Retailers and start-ups have taken notice, and the concepts of mobile location analytics and proximity marketing are emerging out of that.

The long-term effect of the Cold War on science and technology is more profound than Nena’s 99 Luftbalons, or any Oliver Stone Vietnam flick.

If you are reading this, you’re already using Cold War technology; The Internet. That’s not all. A lot of tech and infrastructure we take for granted was developed, or at least conceived, during these tumultuous decades.

Spotlight search in Apple iOS 9, compared to earlier versions, has been made much more prominent and personal. With suggestions from Siri and integration opportunities for third-party apps, iPhone’s search functionality is no longer limited to the scope of Apple’s own apps. In this article, Toptal engineer Richard Forsythe explores some iOS SDK functionalities that allow apps to make content available to the user via Spotlight search.

Maintainable code is something we all desire and there are no shortage of coding principles that promise it. It is not always apparent how tremendously useful these principles are during the early stages of development. Nonetheless, the effort put in to ensure these qualities certainly pay off as the project grows and development continues. In this article, Toptal engineer Adel Fayzrakhmanov discusses how the Single Responsibility Principle is one of the most important aspect in writing good maintainable code.

Whether you’re creating a virtual storefront, deploying an app, or simply doing some third-party testing and development, chances are you need some server muscle. The good news is that there is a lot to choose from. The hosting industry may not be loud or exciting, but it never sleeps; it’s a dog eat dog world, with cutthroat pricing, a lot of innovation behind the scenes, and cyclical hardware updates.

In this article, we take a look at hosting options for freelance software engineers: PaaS, Cloud, VPS, dedicated, and more.

With modern image editing tools, we often take for granted the ability to extract or identify color on some part of any image. However, doing it programmatically is not exactly so straightforward. Camalian, a Ruby gem, changes that, making extracting and manipulating colors in an image as easy as possible. In this article, Toptal engineer Nazar Hussain provides some insight into how various color spaces work, introduces Camalian, and gives an overview of how to use it to build a color-based image search engine in Ruby.

Using modern DevOps Tools like Chef, Docker, Ansible, Packer, Troposphere, Consul, Jenkins, SonarQube, AWS, etc. does not mean that you are applying DevOps principles. DevOps is a way of thinking.

Rapid prototyping and the ability to produce quick visual results are features of many programming languages and frameworks. However, some take it even further by making these their primary goals. Processing, a programming language based on Java, allows its users to code within the context of visual arts and has been designed from the ground up to provide instant visual feedback. In this article, Toptal engineer Oguz Gelal provides a gentle introduction to Processing and some insights into its inner mechanics.

Apple’s iOS 9 and WatchOS 2 updates brings a number of novel features, including improved multitasking for iPads and a host of aesthetic tweaks. However, while iOS 9 is just an incremental update with a focus on the new iPad Pro, WatchOS 2 is not a skin-deep update. Apple has changed the WatchOS architecture and opened up a range of new possibilities for developers.

Real-time applications have already started to dominate the landscape of the Internet. With modern frameworks and standardization of the necessary client-side features, building a real-time web application has become a breeze. However, such web applications still pose unique scalability challenges.

In this article, Toptal engineer Mahmud Ridwan explores the architecture of a simple real-time web application that works using Redis Pub/Sub and doesn’t compromise its horizontal scalability.

Performance and data interoperability are critical to the success of any web application. For web apps that need to support video processing – which is inherently compute- and I/O-intensive – these challenges are particularly acute. In this post, I describe some of my experience successfully incorporating video capabilities into a PHP-based web app, leveraging open source technologies and cloud-based services to the greatest extent possible.

Several factors conspired to stifle Android Wear growth, ranging from lack of Google development, to inadequate hardware. Some of these problems have been addressed, some are being addressed, while others cannot be addressed with currently available technology.

Ruby metaprogramming, one of the most interesting aspects of Ruby, enables the programming language to achieve an extreme level of expressiveness. It is because of this very feature that many gems, such as RSpec and ActiveRecord, can work the way they do. In this article, Toptal engineer Nikola Todorovic demystifies Ruby metaprogramming using some examples that are relevant to everyday programming and aims to bring it closer to average Ruby developers.

NGINX, a sophisticated web server, offers high performance load balancing features, among many other capabilities. Like most other web server software for Unix-based systems, NGINX can be configured easily by writing simple text files. However, there is something interesting about tools that configure other tools, and it may be even easier to configure an NGINX load balancer if there was a tool for it.

In this article, Toptal engineer Mahmud Ridwan demonstrates how easy it is to build a simple tool with a web-based GUI capable of configuring NGINX as a load balancer.

Building cross-platform desktop applications has been something of a nightmare for a very long time, as extreme differences between popular desktop operating systems makes it a challenging feat. However, in light of newer tools and frameworks like Electron, building a cross-platform desktop application has never been easier. In this article, Toptal engineer Stéphane P. Péricat walks us through a step-by-step tutorial to building a cross-platform password key-ring desktop application using technologies that most of us are already familiar with.

Is open source scary? Do developers think that nobody would be interested in their personal projects? What are the fears associated with publishing your own work for the public to see? In this article, Toptal Director of Engineering Anna Chiara Bellini shares how, as an accomplished engineer, she made her first contribution to GitHub. This guide features all the step-by-step basics to getting involved in open source, including everything from what open source software is, to how to start working with Git and GitHub, to actually making meaningful contributions to open source projects.

One of the most misused, misunderstood, and neglected of all the Rails built-in structures is the view helper. Helpers often get a bad reputation for being a dumping ground for one-off methods used across the entire application’s view layer. But what if your helpers could be more semantic, better organized, and even reusable across projects? What if they could be more than just one-off functions sprinkled throughout the view, but powerful methods that generated complex markup with ease leaving your views free of conditional logic and code?

Let’s see how to do this when building an image carousel, with the familiar Twitter Bootstrap framework and some good old-fashioned object-oriented programming.

Every once in a while PHP developers are charged with tasks that require them to extend the functionalities of legacy projects, a task that often includes building REST APIs. Building a REST API for PHP-based projects is challenging, but in the absence of proper frameworks and tools, it can also be a particularly difficult goal to get right. In this article, Toptal engineer Arminas Zukauskas shares his advice, with sample code, on how to build a modern structured REST API around existing legacy PHP projects.

Software performance in production is hard to analyze. Things can go wrong at any time, and code can start executing in ways that weren’t planned for. In these cases, what do we do? In this article, Toptal engineer Juan Pablo Scida analyzes a real scenario of high CPU usage of a web application. He covers all the processes and .NET code analysis involved to identify the problem, explains how the problem was solved, and most importantly, explores why this problem happened in the first place.

Image processing algorithms are often very resource intensive due to fact that they process pixels on an image one at a time and often requires multiple passes. Successive Mean Quantization Transform (SMQT) is one such resource intensive algorithm that can process images taken in low-light conditions and reveal details from dark regions of the image.

In this article, Toptal engineer Daniel Angel Munoz Trejo gives us some insight into how the SMQT algorithm works and walks us through a clever optimization technique to make the algorithm a viable option for handheld devices.

Toptal has a strong remote culture), to say the least. To keep up with each other, we need a tool to keep team members in sync, where we can reach any other person at a moment’s notice. We use Skype as our main communication channel among Toptal’s core team.

Over the years, Skype has grown a lot, and has become a versatile tool that can be used on all of your devices at once, syncing chat amongst them, and providing a simple way to call and share screens. It is a tool that we leverage every day for our internal operations.

As heavy Skype users, there are a few things we’ve noticed that might not be clear to everyone. Here are a few tips on how you and your remote team can get the most of of Skype.

It’s no surprise that more and more people, from all kinds of backgrounds, are deciding to learn to code. But, each person who tackles the task is soon faced with an unpleasant reality: Learning to program is hard. Contrary to expectations, the feeling of “I don’t get it,” may persist unabated long into the journey, making once bright-eyed beginners feel hopeless, lost, and ready to give up.

The moral of the story is this: Be prepared. The path to programmer paradise is a long one, and without the right mindset at the beginning, it can quickly lose its appeal. In this article, I’ll attempt to give you some guidance on what to expect on your journey, how best to go about it, and what tools and resources you may find helpful along the way.

Force Touch is not a new idea. BlackBerry experimented with the concept back in 2008, and a few Android phone makers also examined the possibility of using Force Touch on their products. In fact, Force Touch support has been a part of Android for years; it was introduced in Android 1.0.

Bootstrap, one of the most used HTML/CSS/JavaScript front-end frameworks, offers a little more than just fancy customizable user interface elements. It provides a great starting point for many types of projects, a plethora of components, and many nifty styles predefined for responsive layout and utility classes to help keep your HTML and CSS code clean.

In this article, Toptal designer Lijana Saniukaite walks us through some practical Bootstrap tips and best practices to speed up your application development.

Memory leaks in long running Node.js applications are like ticking time bombs that, if left unchecked in production environments, can result in devastating outcomes. These bugs are often considered to be hard to find. However, with the right tools and a strategic approach, memory leaks can not only be solved but also avoided in the future. In this article, Toptal engineer Vladyslav Millier gives us insight into what memory leaks are, how some sophisticated debugging tools can be used to find memory leaks, and how to plug them once and for all.

The fact that women are underrepresented in tech is nothing new. However, while we’ve seen the gender diversity reports from companies like Google, Facebook, and many more, a look at the number of women in the open source community suggests that the numbers might be worse than these reports imply. In this post, Toptal COO Breanden Beneschott shares the results of a study looking at gender on GitHub and considers a few reasons why GitHub is so male-dominated, including a few ideas on how we can make the open source community a more welcoming place.

The GWT Web Toolkit, formerly known as Google Web Toolkit, is a set of development tools for building and optimizing complex browser-based applications using the Java programming language. What makes GWT not “yet another Java tool to write web apps,” is the fact that the heart of the toolkit is a compiler that converts Java into JavaScript, enabling developers to write front-end web applications while leveraging all of Java’s strengths.

Many developers often overlook, or do not thoroughly think through the implications of open source licenses. Whether you’re planning to open source your own project under one of these licenses, or you intend to integrate some other open source project into one of your own, it’s important to have at least some knowledge of what these licenses are, how they may affect your projects, and how they complement or contradict one another. In this article, Toptal engineer David Marín gives us a comprehensive guide to some of the most popular open source licenses, and several rules of thumb to follow when choosing a license for future open source projects.

When Mike Bostock created D3.js, he introduced a tried and true reusable charts pattern for implementing the same chart in any number of selections. However, the limitations of this pattern are realized once the chart is initialized. In this article, Toptal engineer Rob Moore presents a revised reusable charts pattern that leverages the full power of D3.js.

Today, we will be taking a look at the future of mobile payments and emerging opportunities for developers. Needless to say, with each new opportunity, developers will have to face new challenges.

However, since we are talking about money, I don’t think anyone expects a shortage of software developers eager to learn a few new tricks and get into this space.

Inheriting someone else’s code can be a nightmare, especially when the code is poorly designed and lacks documentation. In this post, Toptal Engineer Juan Pablo Scida provides a case study of how he reengineered a chat server written in Node.js, transforming its original spaghetti code into a cleanly architected and designed piece of software.

Connecting to remote computers and working on them through terminals over a network is something we often take for granted. Technologies that enable us to do this have changed the way we work and have opened doors to amazing possibilities. Although the inner workings of these technologies may seem like obscure knowledge, implementations of many of these technologies are surprisingly straightforward. In this article, Toptal engineer Igor Delac gives us a step-by-step tutorial on how to implement the Remote Framebuffer server-side protocol in Java, allowing Swing-based applications to run and be interacted with remotely using standard VNC clients.

When working on big web applications as a team with other developers, code needs to be scalable and readable. This can be a challenging process when it comes to CSS, although preprocessors like Sass are available. But only using preprocessors will only get you so far. In this article, Toptal engineer Matias Hernandez presents a style guide with advice on how to improve the way you write your code.

CSS preprocessors have been around for quite a while now. These tools, among many things, promise convenience in writing style sheets for the web. However, not everyone is taking advantage of these utilities, and is still resorting to writing vanilla CSS. In this article, Toptal engineer Marcelo Mazza discusses some of the reasons why he thinks Sass is the way to go and why you should be using it in your projects.

Proper test automation is not always easy to achieve and requires almost as much design and thought as needed for the software itself. In the agile way of development tests are an essential ingredient in ensuring quality of software. However, unless these test codes are maintainable, they can prove to be more of a nuisance, especially when it comes to automated testing of modern web applications. This article is an easy introduction to Selenium features Page Object and Page Factory, how they can be used to model web applications, and how to write maintainable test code using them.

One of the hardest things to do in software development is to determine how long and how much it will take to deliver a new software product. Should it be so hard? The answer is not straightforward.

WebRTC has opened doors to all kinds of new peer-to-peer web applications and games that can run in the browser without the need of additional plugins. However, being a relatively new technology, it still poses some unique challenges to developers. PeerJS aims to tackle some of those challenges by providing an elegant API and insulating developers from WebRTC’s implementation differences. In this article, Toptal engineer Mahmud Ridwan provides an introductory tutorial to building a simple, peer-to-peer web game using PeerJS.

Here’s the Vulkan API in a hundred words or less: It’s a low-overhead, close-to-metal API for 3D graphics and compute applications. Vulkan is basically a follow-on to OpenGL. It was originally referred to as the “next generation OpenGL initiative,” and it includes a few bits and pieces from AMD’s Mantle API. Vulkan is supposed to provide numerous advantages over other GPU APIs, enabling superior cross-platform support, better support for multithreaded processors, lower CPU load, and a pinch of OS agnosticism.

The Internet is mankind’s biggest repository of knowledge, information, useful (and useless: think of cat pics) digital content. Today, we will be taking a quick look at something useful and down to earth: free online programming books.

Cars with next-generation connected infotainment systems will create new opportunities on several fronts. In case you already have an infotainment system with a neat touchscreen and GPS in your car, please accept my condolences; it’s about to become as obsolete as a Nokia 3310 compared to an iPhone.

The newest version of the Java platform, Java 8, was released more than a year ago. Many companies and developers are still starting new applications with old versions of Java. There are very few good reasons to do this, because Java 8 has brought some important improvements to the language. I’ll show you a handful of the most useful and interesting ones.

Bitcoin created a lot of buzz on the Internet. It was ridiculed, it was attacked, and eventually it was accepted and became a part of our lives. However, Bitcoin is not alone. At this moment, there are over 700 AltCoin implementations, which use similar principles of CryptoCurrency.

Docker, an open source tool, has changed the way we think about deploying applications to servers. By leveraging some amazing resource isolation features of the Linux kernel, Docker makes it possible to easily isolate server applications into containers, control resource allocation, and design simpler deployment pipelines. Moreover, Docker enables all of this without the additional overhead of full-fledged virtual machines.

The Spring Framework is a powerful, feature-rich, and well-designed framework for the Java platform. It offers a collection of programming and configuration models that aim to simplify and streamline the development process of robust and testable applications in Java. In this article, Toptal engineer Stefan Varga challenges the popular notion of Java as a complicated platform for simple needs, and walks us through a step by step tutorial to building a simple MVC application with the Spring Framework and JPA.

In this article I’ll relate my experience with the popular Unity game development platform and the Model-View-Controller (MVC) pattern for game development. In my seven years of development, having wrestled with my fair share of game dev spaghetti, I’ve been achieving great code structure and development speed using this design pattern.

A large number of modern mobile applications interact with web services in one way or another, and iOS applications are no different. Mantle (a model framework) and Realm (a mobile database) come with the promise of simplifying some of the hurdles in consuming web services through RESTful APIs and persisting data locally. In this article, Toptal engineer Marcin Kmiec shows how to build a simple iOS application using Mantle and Realm and demonstrates how this approach helps to eliminate a large amount of boilerplate code.

OpenGL, a cross-platform API for rendering 2D and 3D graphics, is extremely powerful and yet surprisingly easy to get started with. Although one may find the most common applications of OpenGL and rendered graphics in video games only, in reality there are far more uses. To demonstrate the power of OpenGL, we’ll be building a Mandelbrot set generator on Android using OpenGL ES.

Despite the prevalence of higher-level languages, the C programming language continues to empower the world. There are plenty of reasons to believe that C programming will remain active for a long time. Here are some reasons that C is unbeatable, and almost mandatory, for certain applications.

Google’s new cloud code platform does not appear to be taking on GitHub head on. Instead, Cloud Source Repositories (CSR) will allow users to connect to repositories hosted on GitHub or Bitbucket. However, everything is automatically synced to the Google Cloud Source Repository.

The good news is that a Google CSR can be connected to another Git repository hosted on GitHub or Bitbucket. All changes will be synchronised on both platforms, as you can set Google CSR to automatically mirror from GitHub and Bitbucket.

In today’s world where there are a lot of choices for writing quality software, it’s easy to overlook some tools that are viable options in developing modern software. These software development tools, in competition with each other, often fluctuate in popularity and developer preferences. Many excellent tools are viable options for any given project. This article provides eight reason in favor of the Microsoft stack and why it is still a reasonable choice for software development today.

Whether you’re an avid angler or an app developer, you may be interested in taking a closer look at the development of a fishing app, which involved some of your fellow Toptalers.

The goal was to create an app that would be truly useful in a professional fishing setting, while at the same time meeting a hard deadline. Since Fatsack Outdoors wanted to launch the app at one of the biggest fishing tradeshows of the year, the deadline was non-negotiable.

Detecting objects of interest in images has always been an interesting challenge in the realm of computer vision, and many approaches have been developed over recent years. As mobile platforms are becoming increasingly powerful, now is the perfect opportunity to develop interesting mobile applications that take advantages of these algorithms. This article walks us through the process of building a simple iOS application for detecting objects in images.

Testing back-ends is easy. But testing front-end code is kinda hard. In the ten years I’ve been a developer, I hadn’t found a decent way to test user interaction and view rendering until I started poking at React.

In-memory data collection manipulation is something that we often need to do in data-centric reporting and visualization applications. When needed, we often tend to resort to complex loops, list comprehensions, and other suboptimal means, which can easily end up being a huge mess of hard-to-maintain spaghetti code. Supergroup.js is an in-memory data manipulation library that can be used to solve some common data manipulation challenges on limited datasets.

Ractive.js provides powerful capabilities for web app development in a way that is refreshingly simple to learn and use. In this article, Toptal Engineer Eugene Mirotin walks you through the process of building a simple Ractive search app, demonstrating some of Ractive’s key features and the ways in which it helps simplify web app development. Code samples are provided and explained.

To retain its users, any application or website must run fast. For mission critical environments, a couple of milliseconds delay in getting information might create big problems. As database sizes grow day by day, we need to fetch data as fast as possible, and write the data back into the database as fast as possible. To make sure all operations are executing smoothly, we have to tune Microsoft SQL Server for performance.

In this article, I’ll go through some of the interesting features and libraries that are available to use with React. Even if you don’t plan on using React, taking a look at its ecosystem is inspiring. You may want to simplify your build system using the powerful, yet comparatively easy to configure, module bundler Webpack, or start writing ECMAScript 6 and even ECMAScript 7 today with the Babel compiler. So, let’s explore the React ecosystem!

Programming is about having fun and enjoying the process of creating something cool. That is why we decided to build a bot-vs-bot game platform around Battleship and make it open source. In this article, we take a look at the code and mechanics of the extensible engine behind this platform.

In this article, I will show that unit testing itself is quite easy; the real problems that complicate unit testing, and introduce expensive complexity, are a result of poorly-designed, untestable code. We will discuss what makes code hard to test, which anti-patterns and bad practices we should avoid to improve testability, and what other benefits we can achieve by writing testable code. We will see that writing testable code is not just about making testing less troublesome, but about making the code itself more robust, and easier to maintain.

While Ruby has Rails and Python has Django, the dominant application development framework for Node has yet to be established. But, there is a powerful contender gaining steam: LoopBack, an open source API framework built by StrongLoop, the creators of Express.

Let’s take a closer look at LoopBack and it’s capabilities by turning everything into practice and building an example application.

Ember.js is a comprehensive framework for building complex client-side applications. But, as with any advanced framework, there are still pitfalls Ember developers may fall into. With the following post, I hope to provide a map to evade these. Let’s jump right in!!

Google announced Android M at its annual I/O dev conference in late May, and the new OS is coming to our beloved Android devices later this year. Android 6.0 is more of an evolutionary step, whereas Android 5.0 was a big leap forward thanks to its 64-bit ART runtime and all new Material Design.

However, Android M should not be dismissed as a minor update. In this post, I will try to explain why.

Microsoft Bond is a modern data serialization framework. It provides powerful DSL and flexible protocols, code generators for C++ and C#, efficient protocol implementations for Windows, Linux, and Mac OS X. This article is a quick guide of the features and use of this framework.

Bootstrap is a powerful toolkit. It comes bundled with basic HTML and CSS design templates that include many common UI components. Most of the important pitfalls are mentioned in the Bootstrap documentation, but still some mistakes are pretty subtle, or have ambiguous causes. This article outlines some of the most common mistakes, problems, and misconceptions when using Bootstrap.

This article provides the overview of pain points caused by AngularJS and reasons for switching to React.

Building robust web applications is often a lot about choosing the right tools. Doing so with a combination of tools that ensure both a modern, flexible front-end, and a solid, reliable back-end is something everybody wants. This article demonstrates exactly that trick by combining AngularJS and Play Framework to build a simple blog application.

If you’re doing anything web related, chances are you’ve heard about Bootstrap. Bootstrap is a powerful toolkit - a collection of HTML, CSS, and JavaScript tools for creating and building web pages and web applications. It is a free and open source project, hosted on GitHub, and originally created by (and for) Twitter. If by now you still don’t know what Bootstrap is, or you just want to get a better overview of what it is and what it does best, you’ve come to the right place.

With Dalvik out of the picture, many people expected Google’s new 64-bit capable ART runtime to stick around for years, which it probably will, but it will get a major overhaul in the near future. In addition to offering support for 64-bit hardware, ART also introduced ahead-of-time (AOT) compilation, while Dalvik was a just-in-time (JIT) compiler.

Throw in new 10-core ARM processors and Intel mobile processors based on three different architectures, and you end up with spicy, Google-style hardware gumbo.

Deploying instances of a web application to one or more servers manually can often be a monotonous process, and take up a significant amount of your time. With little effort, it is possible to automate the process of deploying your web application with almost zero human intervention. This article outlines a simple approach to automating web application deployments using GitHub webhooks, buildpacks, and Procfiles.

In Part I of this three-part series, we saw how the free motion of rigid bodies can be simulated. In Part II, we saw how to make bodies aware of each other through collision and proximity tests. Up to this point, however, we still have not seen how to make objects truly interact with each other. The final step to simulating realistic, solid objects, is to apply constraints, defining restrictions on the motion of rigid bodies.

In this article, we’ll discuss equality constraints and inequality constraints. We’ll describe them first in terms of a force-based approach, where corrective forces are computed, and then in terms of an impulse-based approach, where corrective velocities are computed instead. Finally, we’ll go over some clever tricks to eliminate unnecessary work and speed up computation.

Analysts have come to recognize social network data as a virtual treasure trove of information for sensing public opinion trends and groundswells of support. In this article, Toptal Engineer Elder Santos describes the techniques he employed for a proof-of-concept that effectively analyzed Twitter Trend Topics to predict, as a sample test case, regional voting patterns in the 2014 Brazilian presidential election.

Any time you’re physically out of the office or working with someone who isn’t next to you, you’re working remotely. At Toptal, working remotely is a productive and efficient reality that we evangelize to our clients, while practicing what we preach.

In this article, Toptal COO Breanden Beneschott shares great tactics in operating highly collaborative remote teams.

Backbone.js equips the developer with an array of tools that are minimal but extremely flexible. This gives developers the option to design the applications the way they want, but also introduces a number of way things can go wrong. This article outlines a few common mistakes that Backbone.js developers can make, and how they may avoid them.

Log files may very well be one of the most underestimated and underutilized tools at a developer’s disposal. Beyond their value for debugging, with a bit of creativity and forethought, logs files can be leveraged to serve as a valuable source of usage information and analytics. In this article, In this article, Toptal engineer Ilya Sanosyan provides a practical guide to maximizing the value we get from our logs.

Windows 10 represents a departure from Microsoft’s traditional OS strategy. It’s not just a new operating system, it’s an automatic and free update for millions of Windows 8.1 devices. It’s also designed to address a number of user complaints related to the Windows 8.x UI. The changes aren’t just skin deep, as Windows 10 is not a mere redesign with a new UI and fancier apps; it might even mark the start of a new era for Microsoft, and in this post I will explain why.

AngularJS is a very powerful framework. It is the third most starred repository on GitHub. It is not difficult to start using, but the goals that it is intended to accomplish demand comprehension. No longer can we ignore memory consumption, because it will not reset on navigation anymore. This is the vanguard of web development. Let’s embrace it!

Machine learning has changed the way we deal with data. Data driven problems, that are difficult to solve using standard methods, can often be tackled with much more ease using machine learning algorithms. In this article, we will explore Azure Machine Learning features and capabilities through solving one of the problems that we face in our everyday lives.

We will see technology push its way forward and society will be the better for it. The exciting question is who will lead this wave of disruption?

C++ is a general purpose programming language that offers great flexibility when it comes to system programming and application development. The language, however, comes with some pitfalls requiring attention from developers to ensure quality programming. This article explains how ten of the most common C++ developer mistakes can be avoided.

Google wants to bring Android to everything from phones and watches, to cars and smart television sets. Unlike Google TV, Android TV is much closer to standard Android. It runs Android 5.0 (at least in the initial launch version) and can be used on new TVs, as well as on standalone devices.

Android TV is not just about improving the way people consume TV content, it’s more about changing the way they do it.

In today’s data driven world, researches are busy answering interesting questions by churning through huge volumes of data. Some obvious challenges they face are due the sheer size of dataset that they have to deal with. In this article, we take a peek at a simple business intelligence platform implemented on top of the MongoDB Aggregation Pipeline.

While the Apple Watch is on track to be a commercial success for Apple and its shareholders, technologists are still not entirely convinced smartwatches have what it takes to conquer the market, at least not yet.

What does this mean for developers? What are the implications for other smartwatch platforms and companies behind them?

Apache Lucene is a powerful Java library used for implementing full-text search on a corpus of text. With its wide array of configuration options and customizability, it is possible to tune Apache Lucene specifically to the corpus at hand - improving both search quality and query capability.

This article gives us a glimpse of the simplicity and ease of customization of the Apache Lucene analysis pipeline.

iOS 8 introduced a new concept called App Extensions. This new feature did not break down the walls between the applications, but it opened a few doors providing gentle yet tangible contact between some apps. The latest update gave us an option to customize the iOS ecosystem, and we are eager to see this path opening up as well.

Developers often automate certain repetitive and tedious tasks to save time as well as to stay focused on the task at hand.

This article demonstrates how simple and easy it is to use Gulp as a build tool.

Texts are an integral part of user interfaces. In many cases, text annotation plays a vital role in grabbing the user’s attention or allowing the user to decorate and highlight the content they produce.

In this article, we walk through the ins and outs of an open source JavaScript library built for annotating texts on the web.

You are what you read – and most Toptal members and blog subscribers are software developers. So what do you read? Where do professional developers get the latest information about how their peers work and think?

Today, we will be taking a look at a small selection of popular developer blogs frequented by Toptal developers. We’re counting on you (our readers) to expand the list in the comment section.

Location-based applications on our mobile devices have changed the way we interact with mobile technology. The list of these applications is extensive and has had a major impact on our lives.

This article walks us through a step-by-step tutorial of how to determine the location of an Android device using Google Location Services API.

The extremely diverse and fragmented Android ecosystem poses certain challenges when it comes to testing. In this article, we take a look at some approaches that can be effective with tackling these challenges and ease the process of writing and automating tests.

Passwordless authentication has been the Holy Grail of security for years, but progress has been painfully slow. Until a few years ago, the technology to implement passwordless logins on a grand scale simply wasn’t available.

However, the industry juggernaut is slowly but surely changing this. There are a few technical, legal and even ethical considerations to take into account, but be as it may, biometric, passwordless authentication is here to stay.

Toptal has taken its place as one of the strategic partners in Facebook’s effort to connect the world. Our vision of a distributed and office-less company with developers spread all over the globe has proven to be an amazing match to Facebook’s attempts to connect people worldwide.

Face it, you’re a software engineer, not a graphic designer. When you need to write a manual, technical document, or report, you just want to write it and be done with it. Especially for you as a software engineer – who is not put off by needing to learn and use some basic syntax conventions – Markdown can be the path of least resistance between what you want to write and getting it written.

You might presume that Non-Disclosure Agreements (NDAs) have been widely accepted in the tech world as a means to protect sensitive and potentially valuable information from theft and abuse. Not so fast.

Jones Day Corporate Associate Bret J. Stancil examines software developer NDAs for Toptal blog followers in a must-read post for anyone faced with the prospect of signing an NDA.

Node.js, the cross-platform runtime environment, has seen its fair share of praise and criticism for what it offers to developers. Often, reasons for such criticisms are rooted in how developers use/misuse the language.

This article explores ten common mistakes that Node.js developers make and how to avoid them.

Meteor makes developing web applications simple. It’s easy to learn, and comes with a pre-built arsenal of powerful functionalities. In this article, we will walk through a detailed tutorial for building a simple real-time web application.

In this post, Toptal engineer Radek Ostrowski introduces Apache Spark – fast, easy-to-use, and flexible big data processing. Billed as offering “lightning fast cluster computing”, the Spark technology stack incorporates a comprehensive set of capabilities, including SparkSQL, Spark Streaming, MLlib (for machine learning), and GraphX. Spark may very well be the “child prodigy of big data”, rapidly gaining a dominant position in the complex world of big data processing.

Authentication is one of the most important parts of any web application. For decades, cookies and server-based authentication was the easiest solution. However, handling authentication in modern Mobile and Single Page Applications can be tricky and demand a better approach. One of the best known solutions to authentication problems for APIs is the JSON Web Token (JWT).

Over time, the race between DirectX and OpenGL has caused these technologies to become more accessible to developers, along with better documentation and an easier process of getting started with them. This tutorial article shows you how to build a 3D modeling application that generates and renders 3D texts from user inputs.

In an attempt to make web applications a lot more dynamic, front-end Javascript frameworks like Angular.js, Backbone.js and Ember.js have gained a lot of popularity. However, these frameworks often require a back-end application to be useful, so they are used in conjunction with web frameworks like Ruby on Rails and Django.

On the other hand, Volt is capable of managing the back-end and a dynamic front-end; since both functionalities are tightly integrated into its core.

Describing Nvidia Shield as a mere Android console would not do it justice. The console relies heavily on streaming and cloud computing, so it shouldn’t not be viewed as another standalone device.

Nvidia sees Shield as Netflix for games, as a comprehensive Gaming-as-a-Service (GaaS) platform. While it’s still part of the Android ecosystem, Shield could be bad news for some Android game developers, but it also creates a range of new and exciting opportunities.

AllcountJS is an emerging open source framework built with rapid application development in mind. It is based on the idea of declarative application development using JSON-like configuration code that describes the structure and behavior of the application.

In this article, we walk through a step-by-step tutorial for prototyping a data oriented web application using AllcountJS.

After a couple of years of bullish forecasts and big promises, security seems to be the biggest IoT concern. The first few weeks of 2015 were not kind to this emerging industry, and most of the negative press revolved around security.

Was it justified? Was it just “fear, uncertainty and doubt” (FUD), brought about by years of hype? It was bit of both; although some issues may have been overblown, the problems are very real, indeed.

In Part I of this three-part series on game physics, we explored rigid bodies and their motions. In that discussion, however, objects did not interact with each other. Without some additional work, the simulated rigid bodies can go right through each other.

In Part II, we will cover the collision detection step, which consists of finding pairs of bodies that are colliding among a possibly large number of bodies scattered around a 2D or 3D world.