What is the difference between the React Native Bridge and the New Architecture (JSI)?

The Bridge is asynchronous and serialized, while JSI allows direct, synchronous interaction between JavaScript and native code.

The traditional React Native Bridge sends batched, serialized JSON messages between JS and native threads, which introduces latency and overhead. The New Architecture introduces JSI (JavaScript Interface), allowing direct memory references and synchronous communication between JS and native modules. This reduces serialization cost and improves performance significantly, especially for animation-heavy and real-time apps.