Toptal Engineering Blog

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.

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.

Uploading a video to YouTube seems like a simple enough task, but non-existent documentation and unmaintained libraries can make even the simplest of tasks seem daunting.

In this post, Toptal Freelance Django Developer Ivan Carmo da Rocha Neto guides you through how to post YouTube videos from your Django app.

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.

Moving to a microservices architecture often raises the question: What is the best environment to stabilize services? Here’s how and why you should use Kubernetes, Docker, and CircleCI to containerize and deploy apps.

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

In this article, Toptal AI expert Necati Demir, PhD, moves past the evil artificial intelligence of science fiction to discuss the current algorithm-based prediction AI, the economics of AI, and the economic benefits of artificial intelligence.

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.