Toptal Engineering Blog

As applications become more complex, having good logs can be very useful, not only when debugging but also to provide insight in application issue/performance.

The Python standard library comes with a logging module that provides most of the basic logging features and is very handy but contains some quirks that can cause hours of headaches

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.

For a large codebase, managing database schema can become tedious, especially if you maintain multiple testing environments or customers that update the product at different paces. Sometimes, documenting the latest schema or database changes isn’t enough.

In this article, Toptal Database Engineer Ivan Pavlov introduces us to concepts that help manage database states.

Angular 5 is a new version of the Angular framework developed by Google. Angular 5 comes with improvements including optimized builds and faster compile times, but in this Angular 5 tutorial, we are going to build a notes app from scratch. If you’ve been waiting to learn Angular 5, this tutorial is for you.

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.

In this article, Toptal Freelance Software Engineer Piotr Gaczkowski explains how to make the most out of command line tools and lists some of the best tools out there.

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.

Elm is a purely functional, strongly typed, reactive, and event-driven web client language. It takes a step back from the norms and really changes the way you reason about and program web application front-ends.

In this article, Toptal Freelance Software Engineer Vuk Djapic takes you through the exotic concepts of Elm and its pros and cons in real world use.