Toptal Engineering Blog

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.