Toptal Engineering Blog

F# is a strongly typed, multi-paradigm programming language with imperative, functional, and object-oriented programming methods.

In the first part of our F# tutorial series, Toptal Freelance Software Engineer Shanglun Wang demonstrates how to get started and create a simple app using nothing but F#.

Keeping your Android codebase maintainable as your codebase grows can be a challenge. In this article, Toptal Freelance Android Developer Abhishek Tyagi shows how to combine MVVM with Clean Architecture—the latter as described by Robert C. Martin—to write decoupled, testable, and maintainable code.

As UX strategy and design become increasingly important, the challenge of incorporating UX specialists into Agile methodologies becomes equally important.

In this article, Toptal Freelance UX Designer Debbie Levitt explains how UX designers and creative teams can be effectively incorporated at all stages of Agile development.

iOS developers love the power of UIKit, and animating a UIView is usually fairly easy. However, if you want to chain animations together and set up dependencies between them, your code can quickly become difficult to read with many nested closures and indentation levels.

In this article, I’ll explore how to apply the power of a reactive framework such as RxSwift to make that code look much cleaner as well as easier to read and follow. My client wanted a story told through a sequence of animations rather than by playing a pre-rendered video, and with RxSwift, we easily tweaked it to perfection.

Magento is an extremely popular eCommerce platform used by businesses of all sizes, so what can we do to make it faster and more efficient? In this article, Toptal Freelance Magento Developer Paul Mestereaga explains what you can do to improve the performance of your Magento site.

Code reuse turns lazy developers into efficient geniuses. Imagine if you could write the majority of your code once and run it on the web and native mobile—both iOS and Android.

In this article, Toptal Freelance Dart Developer Marko Perutović introduces us to the BLoC pattern, whereby you can isolate your business logic in pure Dart and reuse it in both Flutter and AngularDart.

JavaScript is an oddball of a language with numerous approaches to almost any problem. When ES6 added the “class” keyword, did it save the day or just muddy the waters? In this article, Toptal Freelance JavaScript Developer Justen Robertson explores OOP in modern JS.

Project management tools have dramatically transformed the way software is engineered, but which one should you use, and when?

In this article, Toptal Freelance Developer Juan Carlos Arias Ambriz outlines the differences between Jira and Trello and explains how you should choose between them.

The whole point of smart contracts is that they need to be more secure and efficient than traditional contracts. So where do smart contract oracles fit in?

In the final installment of our three-part series, Toptal Blockchain Developer John R. Kosinski explains the role of oracles in the evolution of trust.

ClojureScript is the tool of choice for front-end developers who have tried it. Recently in this series, we showed how to use it to get started with React. In today’s tutorial, Toptal Freelance Clojure Developer Luke Tomlin dives into how to use Redux for React state management in ClojureScript.

Real-time data-driven apps create new challenges in the way we structure our programs, especially on mobile. In this article, Toptal Freelance iOS Developer Lucas van Dongen implements an iOS chat app, comparing the classic MVC approach with a static immutable MVVM pattern.

Writing an application is only part of the story. In order for it to be of value, it needs deploying somewhere it can scale; it has to run with high availability, have backups, and so on. Deployment and infrastructure management isn’t a simple process. And Terraform does nothing to hide the complexity. However, it does make your infrastructure declarative and reproducible, like your code.

In this article, Toptal Freelance DevOps Engineer Radosław Szalski teaches us what Terraform is, how its components work, and how to configure an entire AWS Cloud solution in minutes using its configuration language.

Node 8 has brought significant performance and feature upgrades. Should you use it on new projects? Is it worth upgrading existing codebases? In this article, Toptal Freelance JavaScript Developer Youssef Sherif gives a tour of Node 8’s biggest changes and what they mean for your project.

Entity Framework is a great tool, but in some cases its performance is slow. One such case arises when complex queries use “Contains”.

Join Toptal .​NET Developer Anton Shkuratov in exploring how performance issues can be mitigated and finding the best approach to this type of complex queries.

Solidity is the programming language of choice for Ethereum and the de facto industry standard for smart contract development.

In the second article of our three-part series, Toptal Blockchain Developer John R. Kosinski takes a closer look at Solidity quirks and features, explaining how to make the most of it.

If you’re searching for the holy grail of bug-free code in JavaScript, Python, Ruby, Swift, and/or Scala, look no further! This monad tutorial by Toptal Freelance Functional Programmer Alexey Karasev takes you from category theory to the practical implementations of the Option/Maybe, Either, and Future monads, plus a sample program—in all five languages.

Oracles are changing the way we view and create smart contracts. How do we implement them in Ethereum, using nothing but Solidity and standard dev tools?

In the first article of our three-part series, Toptal Blockchain Developer John R. Kosinski explains how to get started and compile a smart contract with oracles.

Traditionally, connecting devices for peer-to-peer communications has been a tedious task: An application needs to discover what’s around it, open connections on both sides, and then maintain them as network infrastructure, connections, distances, etc. Realizing the difficulties inherent in these activities, in iOS 7 and macOS 10.10 Apple introduced its MultipeerConnectivity framework.

Join Toptal Freelance iOS Developer Ben Gottlieb as he explains what MultipeerConnectivity is, and teaches us how to use it.

Let’s face it, robots are cool. In this post, Toptal Engineer Nick McCrea provides a step-by-step, easy-to-follow tutorial (with code samples) that walks you through the process of building a basic autonomous mobile robot.

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.