Back-end posts

The Model-View-Controller (MVC) design pattern is great for the longevity and maintainability of an iOS application’s codebase… but you may find yourself adding similar functions to multiple models as your app grows. In cases such as networking, moving common logic out of your model classes and into singleton helper classes can be a better approach. In this article, I’ll teach you how to set up a centralized singleton networking object that, decoupled from micro-level MVC components, can be reused throughout your application.

Sharing related information among isolated systems has become increasingly important. There are many methods to choose from to perform that task for SQL Server, but it’s important to know which is better for each use case.

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.

Write better Ruby code by leveraging its metaprogramming features. In this article, you will learn how to create your own Ruby domain specific language (DSL).

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?

Laravel is a PHP framework developed with developer productivity in mind. Written and maintained by Taylor Otwell, the framework is very opinionated and strives to save developer time by favoring convention over configuration. The framework also aims to evolve with the web and has already incorporated several new features and ideas in the web development world—such as job queues, API authentication out of the box, real-time communication, and much more.

In this article, we’ll explore the ways you can build—and test—a robust API using Laravel. We’ll be using Laravel 5.4, and all of the code is available for reference on GitHub.

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.

Build a bot that analyzes the sentiment of incoming email messages using Recursive Neural Tensor Networks from the Stanford NLP library.

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.

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.

Widgets play a pivotal role in Magento development, as they’re often used to display targeted content and provide crucial front-end functionality. Magento 2 offers a lot of widget possibilities out of the box, and also allows developers to unlock more features using custom widgets.

In this article, Toptal Freelance Software Engineer Vivek Khatri provides an overview of widget implementation in Magento 2, starting with the basics and culminating in custom widget design.

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.

PhalconPHP will make your high-load application fast and easy, it’s one of the fastest MVC frameworks for PHP available. It’s written in C and supplied as a compiled PHP extension, so it doesn’t need to be interpreted at every request. Consider PhalconPHP for your next project, you won’t regret it.

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.

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.

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.

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.

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.

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.

C is often called a middle-level computer language as it combines the elements of high-level languages with the functionalism of assembly language. C allows the manipulation of bits, bytes, and addresses - giving the programmer more control over exactly how the program will behave and a more direct access to the mechanics of the underlying hardware.

C was created, influenced, and field tested by working programmers. The end result is that C gives the programmer what the programmer wants.

C++ is an enhanced version of the C language. C++ includes everything that is part of C and adds support for object-oriented programming (OOP). In addition, C++ also contains many improvements and features that make it a “better C”, independent of object oriented programming.

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.

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.

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.

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, Toptal 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.

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.

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.

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.

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.

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.

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.

Many product owners don’t have a technical background and thus often find themselves unprepared and scrambling when it comes time to bring on a new development team. This often results in hindered progress, wasted time, and frustration for everyone involved. If this sounds like it could be you, either now or in the future, then you should be somewhat concerned.

In this blog post, Toptal Freelance Software Engineer Carlos Ramirez III will walk you through the various steps of a typical transition process in project management so you can prepare for this eventuality and make the transition as smooth as possible.

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.

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”.

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.

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.

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.

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.

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.

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.

When dealing with time consuming, resource intensive tasks, most PHP developers are tempted to choose the “quick hack route”. We’ve all used “ini_set(‘max_execution_time’, HUGE_INT);” before, but it doesn’t have to be this way.

In today’s tutorial, PHP developer Daniel Gheorghe demonstrates how an application’s user experience may be improved by separating long-running tasks from the main request flow using Laravel.

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.

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.

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.

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.

Small teams frequently have to compete with bigger, more structured organizations who are capable of allocating more resources to project management, and software release management in particular. This means that small teams, or even individual developers, need to properly organize and execute their release process in order to keep up.

In this article, Toptal Freelance Software Engineer Lucas Mancini focuses specifically on small startups, teams that don’t have, or can’t afford, DevOps support, or teams that don’t have a formal process defined for releasing new versions of their product. The author provides a suggested checklist method to manage releases, tailored to match his past experience working on different projects, together with some recommended best practices and guidelines.

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.

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.

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.

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.

Boring. That’s a word many people use to describe the server industry, although unexciting and uneventful would be a better fit. This is not necessarily a bad thing, because when something “exciting” happens to a server, it usually involves blue smoke and downtime. Luckily, the server space is about to get a bit more exciting, thanks to the introduction of servers based on ARM processors.

In this post, Toptal Technical Editor and resident chip geek Nermin Hajdarbegovic explains why ARM processors could end up powering a server near you, and what this means for the software industry. The potential implications of ARM servers are huge, but there is no cause for alarm. This industry segment does not tend to evolve fast, and developers will have plenty of time to get ready.

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.

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.

In this article, Toptal engineer Ivan Voras provides a useful overview and comparison of multi-processing network server models, with the goal being to take some of the mystery out of writing high performance networking code. The article is intended for “system programmers”, i.e., back-end developers who will work with the low-level details of their applications, implementing network server code.

Although the old, standardized security approaches work with REST services, they all have problems that could be avoided by using a better standard. For this, JWT arrives just in time to save the day.

In this article, Toptal engineer Dejan Milosevic guides us on how to implement a JWT token-based REST API using Java and Spring Security.

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.

Developers often work on only one machine, and have their whole development environment on that machine. Testing database replication before deploying changes in this kind of a development environment can be a challenging task.

In this article, Toptal engineer Ivan Bojovic guides us through a step-by-step tutorial on how to implement MySQL master-slave replication on one machine.

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.

Integrating social network login in web applications directly using their SDKs can be a time consuming task. The fact that these SDKs keep changing every now and then doesn’t help either.

In this article, Toptal engineer Son Nguyen Kim provides us with an in-depth tutorial on how to use Satellizer, a feature-rich AngularJS library to integrate Facebook Login in an AngularJS web app.

Developers sometimes run into tasks that require access to email mailboxes. In most cases, this is done using the Internet Message Access Protocol, or IMAP. As a PHP developer, I first turned to PHP’s built in IMAP library, but this library is buggy and impossible to debug or modify. So today we will create a working IMAP email client from the ground up using PHP. We will also see how to use Gmail’s special commands.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Toptal engineer Jurgens du Toit looks at the possibility of using Logstash to regain control of your inbox and make your error emails manageable again, all without changing a single thing in your app.

Logstash can effectively leverage the power of Elasticsearch and Amazon SNS to streamline email notifications and save time.

A business rules engine is a tool for executing business rules. Business rules are composed of facts and conditional statements. Any “if-then” statement that appears in traditional business logic qualifies as a business rule.

The Internet is becoming “smarter” every day. The video-sharing website that you frequently visit seems to know exactly what you will like, even before you have seen it. The online shopping cart holding your items almost magically figures out the one thing that you may have missed or intended to add before checking out. It’s as if these web services are reading your mind - or are they?

Turns out, predicting a user’s likes involves more math than magic. In this article we will explore one of the many ways of building a recommendation engine that is both simple to implement and understand.

A thorough and practical introduction to concurrent and parallel programming in Ruby, presenting and contrasting a number of techniques and options available, from the standpoints of both performance and complexity. Discusses forking, multithreading, the Global Interpreter Lock (GIL), and more.

You hear a familiar song in the club or the restaurant. You listened to this song a thousand times long ago, and the sentimentality of the song really touches your heart. You desperately want to heart it tomorrow, but you can’t remember its name! Fortunately, in our amazing futuristic world, you have a phone with music recognition software installed, and you are saved.

But how does this really work? Shazam’s algorithm was revealed to world in 2003. In this article we’ll go over the fundamentals of that algorithm.

Git can support your project not just with version control, but also with collaboration and release management. Understanding how workflow patterns can help or hinder a project will give you the knowledge to evaluate and adapt your project’s Git processes effectively.

Why are Rails Engines not used more often? I don’t know the answer, but I do think that the generalization of “Everything is an Engine” has hidden the problem domains that they can help to solve.

For all too many companies, it’s not until after a breach has occurred that security becomes a priority. An effective approach to IT security must, by definition, be proactive and defensive. This post focuses on 10 common and significant web-related IT security pitfalls to be aware of, including recommendations on how they can be avoided.