There are lots of languages used at Stripe! The two most common are Ruby and JavaScript.

Our Ruby code is very vanilla and powers most of our back-end services, including the dashboard, our API, stripe.com, and more.

Our JavaScript is not vanilla. We use ES2017, plus Flow (type annotations) and JSX (for React). We also have a fair amount of Coffeescript left over from back when that was cool.

Besides Ruby and JavaScript, you’ll find Scala and Go. These are infrequent and were chosen specifically for projects that can take advantage of their best features. Every now and again I’ll spot the odd Python script, but that’s a rarity.