Slack is an application for team communication. Users chat across mobile devices, web browsers, and a desktop application, which means Slack has three places to deploy on rather than two. And the desktop apps on Windows, Mac, and Linux are not identical, so Slack has even more places to deploy.

With so many different runtime environments, Slack needs to make technology choices that reduce the chance of errors. TypeScript allows for static typing of JavaScript. The extra compilation step checks the types of variables being passed between different places–so the errors will be discovered at compile time. In an untyped world, those errors might occur at runtime. TypeScript also unlocks the ability to put JavaScript code in an IDE, allowing for more efficient development.

Felix Rieseberg is a desktop engineer at Slack, and in today’s episode he explains the unique challenges of building Slack, and why the team moved from JavaScript to TypeScript.

Show Notes

TypeScript at Slack – engineering blog

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