Toptal Engineering Blog

The Toptal Engineering Blog is a hub for in-depth development tutorials and new technology announcements created by professional software engineers in the Toptal network.

authors are vetted experts in their fields and write on topics in which they have demonstrated experience. All of our content is peer reviewed and validated by Toptal experts in the same field.

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Big Data Architecture for the Masses: A ksqlDB and Kubernetes Tutorial

Today’s cloud building blocks empower any size team—even a lone engineer—to build big data solutions. Learn how to use open-source tools to create scalable architecture for your next project.

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Dmitrii Bolotov

Dmitrii is a solution architect and developer with more than 11 years of experience and expertise in SQL, NoSQL, and Kubernetes. He built big data architecture at Videoland, founded and acted as CTO for Deetask, a Vietnamese marketplace app similar to Thumbtack, and holds a master’s degree in computer science from Izhevsk State Technical University.

Demystifying Debugging With React Developer Tools

Bugs are often buried deep within the code and software developers spend a great deal of time hunting them down. Many software developers debug front-end code using the browser’s console logging, but this is cumbersome and inefficient. Discover how React Developer Tools can speed up the debugging process by providing powerful tools to inspect components, monitor state and props, and track rendering and performance.

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Teimur Gasanov

Teimur is a software developer specializing in web application development. He has extensive experience developing with front-end technologies, such as React, TypeScript, and JavaScript, and has implemented applications for innovative companies such as Klarna, where he designed interfaces for interacting with digital wallets from Apple, Google, and Samsung.

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Kotlin vs. Java: All-purpose Uses and Android Apps

Kotlin and Java are two powerful general-purpose languages popular for Android and beyond. We’ll discuss their top features and differences, then focus on how to smoothly transition between the two.

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Gabe Giro

Gabriel is a senior Android engineer with nine years of experience building apps from scratch in Kotlin and Java, and facilitating conversions between the two languages. Gabriel has worked on multimillion-dollar apps and has industry experience at companies like HBO and Yahoo.

How to Deploy Django on Heroku: A Pydantic Tutorial, Part 3

Heroku makes deployment—and redeployment—incredibly simple. Explore Heroku’s Django hosting in this tutorial, and see for yourself.

9-minute readContinue Reading

Arjaan Buijk

Arjaan is a senior engineer and data scientist who creates mission-critical, Python-based cloud solutions focused on Rasa for international banks and insurance companies. He architects and teaches large-scale Kubernetes solutions.

Investing in Unit Testing: Benefits and Approaches

Stakeholders demand quick fixes for a buggy app release. Such patching is costly, and does not always offer a complete solution. Break the cycle with unit testing, a worthwhile investment in project quality.

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Dacian Florea

Dacian is a senior full-stack mobile applications developer and a contributor to the Flutter framework. He specializes in rigorous testing solutions that help companies around the world design and deliver quality software applications.

Building Simple and Efficient Components With React-Bootstrap

With websites being viewed on so many different types of devices and in so many screen sizes, a responsive user interface is more important than ever. Leverage the power of two popular technologies with the React-Bootstrap library for performant, responsive components.

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Matej Bilić

Matej is a full-stack developer with expertise across a variety of back-end and web technologies, including React, React Native, Bootstrap, and Django. He specializes in advanced web applications and built a global, bilingual travel and tourism app using React and React Native.

Heavy Computation Made Lighter: React Memoization

Unnecessary component computation drastically reduces application performance. Avoid this pitfall by using React memoization hooks and render component caching.

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Prateek Karki

Prateek is a React engineer with more than seven years of experience in web development. An expert in delivering a top-tier user experience through the union of engineering and design, he has worked on enterprise-scale solutions in diverse industries, including roles at Precision Drilling and Fresh Tracks Canada.

React Router Tutorial: Redirect Like a Pro

Naive React routing increases risk and maintenance. This tutorial provides a full exploration of routing approaches, achieving an elegant solution that seamlessly fits into any React code base.

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Nathan Babcock

Nathan is a front-end and full-stack developer, and an expert in streamlining UI/UX with React. As the lead design engineer at Motorola Solutions, he marshaled an internal product that included React, Angular, Svelte, and native web components from prototype to corporatewide deployment—garnering more than 100,000 downloads.

Listening is everything—especially when it comes to effective marketing and product design. Gain key market insights from social media data using sentiment analysis and topic modeling in Python.

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Federico Albanese

Federico is an expert Python developer and data scientist who has worked at Facebook, implementing deep learning models. He is a university lecturer, and his PhD research focuses on natural language processing and machine learning.

Explore X (formerly Twitter) data clusters to uncover user behaviors (e.g., repost and reply patterns) within online communities. This guide focuses on a politically charged data set to illustrate the process of visualizing and analyzing social data.

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Juan Manuel Ortiz de Zarate

Juan is a developer, data scientist, and doctoral researcher at the University of Buenos Aires where he studies social networks, AI, and NLP. Juan has more than a decade of data science experience and has published papers at ML conferences, including SPIRE and ICCS.

Supply Chain Optimization Using Python and Mathematical Modeling

Improving supply chains is a top priority worldwide. Discover how mathematical optimization and Python coding can help keep a complex supply chain competitive.

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Michael Hopf

Michael is a developer, data science consultant, and expert in supply chain optimization for heavy industry clients in rail, vessels, and mining. He has a PhD in mathematical optimization and was a consultant in the analytics practice of McKinsey & Company’s QuantumBlack for four years.

Unit Testing in Flutter: From Workflow Essentials to Complex Scenarios

Incorporate comprehensive unit testing into your Flutter project to ensure best practices and reduce bugs before—not after—the app’s release.

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Dacian Florea

Dacian is a senior full-stack mobile applications developer, a Flutter expert, and a contributor to the Flutter framework. He helps companies around the world design and implement quality software solutions and deliver excellent user experiences.

Identifying the Unknown With Clustering Metrics

Clustering in machine learning has a variety of applications, but how do you know which algorithm is best suited to your data? Here’s how to amplify your data insights with comparison metrics, including the F-measure.

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Surbhi Gupta

Surbhi is a data scientist and developer with expertise in machine learning and robotics. A former senior data science engineer at Utopia Global, her experience ranges across ML fields including NLP, computer vision, and OCR. She has a master’s degree in mechatronics, and has published research in the field of robotics and optimization.

Future-proof Your Android Code, Part 2: Functional Reactive Programming in Action

The functional reactive programming (FRP) paradigm is becoming increasingly mainstream. In this installment, we discuss FRP essentials like system design and libraries, and implement a sample application.

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Iliyan Germanov

Iliyan is an Android developer and CTO who has founded four startups and created several top-rated apps, including Ivy Wallet, which has received 10 YouTube tech community “best UI/UX” awards. He specializes in functional programming, UX, Kotlin, and Haskell.

The Foundations of Functional Reactive Programming in Android

This tutorial explores the mathematical concepts behind two key programming paradigms, functional programming and reactive programming, so you can build long-lasting Android architecture.

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Iliyan Germanov

A .NET Programmer’s Guide to CancellationToken

Microsoft created a standardized cancellation implementation that has far-reaching capabilities beyond its original use case—from application run states and timeouts to interprocess communications.

7-minute readContinue Reading

Davit Asryan

Davit is a software engineer specializing in .NET and C#. He has created enterprise software for companies like Veritas, serving as a Senior Principal Software Developer. Davit has overseen complex architecture migrations and worked on multimillion-dollar projects.

Toptal Engineering Expert

Gabriel Courtemanche

Gabriel is a highly efficient and reliable professional who possesses a broad skill set for web application development. He's been working on a range of products and clients—from working on scalability problems in production engineering teams at Shopify and Autodesk to launching new applications for startups. Most of his work consists of leading technical teams, by creating an easy development environment, fixing technical debts, providing best practices code examples, and mentoring devs.