React & React Native

React is a JavaScript library for creating highly dynamic, interactive, user-friendly interfaces both for web browsers and mobile applications. Originated at Facebook and open-sourced in 2013, React is now the most popular and widely-used frontend framework, used by around 75% of all IT businesses.

We've been using React since 2015 and it's now our go-to framework for frontend development. We use TypeScript, a derivative of JavaScript which adds static typechecking to the language and makes our frontends more reliable and stable.

For mobile apps, we use React Native, another Facebook-originated open-source project that uses patterns and ideas from React, but allows us to create cross-platform (iOS and Android) native apps from a single codebase, avoiding the need to build everything separately for each platform.