React Native is a library that allows developers to build native mobile apps using JavaScript and React. It renders React components as native iOS and Android elements. While this allows sharing of code and faster iteration, there are some challenges with synchronizing threads between the JavaScript logic and native UI threads. The bridge aims to minimize this by batching and asynchronously sending messages, but some events still need to block. Future rearchitecting ideas include handling synchronous events, prioritizing renders, and using a lighter bridge.
