React Native Blog Oct 23, 2024

The New Architecture is Here: React Native

Article Summary

After 6 years of development, React Native's complete ground-up rewrite is finally here. The New Architecture in version 0.76 fundamentally changes how JavaScript and native code communicate—and the performance gains are real.

The React Native team at Meta has shipped the New Architecture as the default in React Native 0.76, marking the completion of a massive rewrite that began in 2018. This release includes full React 18 support, a new renderer written in C++, and eliminates the async bridge that previously bottlenecked performance. Over 850 libraries already support it, including all packages with 200K+ weekly downloads.

Key Takeaways

Critical Insight

React Native 0.76 delivers production-ready concurrent rendering, type-safe native modules, and cross-platform C++ code sharing that companies like Meta, Expensify, and Kraken are already using at scale.

The article reveals how the new Event Loop implementation closes a critical gap between React DOM and React Native that's existed since the beginning.

About This Article

Problem

The old architecture used an asynchronous bridge that created serialization bottlenecks and synchronization issues between JavaScript and native layers. When states got out of sync, there was no good way to fix it, which led to visual bugs like empty list frames and UI jumps from intermediate states.

Solution

Meta's team built a new Native Module System in C++ with a JavaScript Interface (JSI) that allows synchronous communication. They replaced the async bridge with direct native access and added Codegen to ensure type-safe contracts between JavaScript and native code.

Impact

The new system stopped cross-boundary type errors from being a major crash source in cross-platform apps. It made layout reads possible across multiple threads synchronously and cut app startup time by removing bridge initialization overhead. The system works with 850+ compatible libraries, including all packages with 200K+ weekly downloads.