The New Architecture of React Native

let’s learn Something old

No, you haven’t read it wrong; it was indeed written “old.” But why mention the “old” while describing the new architecture? The answer is simple: understanding what’s new in React Native becomes far easier when you understand what’s “old.” This blog will walk you through the changes in React Native’s architecture by revisiting the past and comparing it with the present.

And as always, let’s start with the Three W’s: What, Why, and When.

What Was React Native’s Old Architecture?

React Native was initially designed with a concept called the Bridge.

The Bridge allowed communication between the JavaScript (JS) thread and the Native (Android/iOS) thread. While this approach enabled React Native to work cross-platform, it came with some inefficiencies:

• Asynchronous Communication: The JS and Native threads communicated via asynchronous batched messages, leading to delays.
• Performance Bottlenecks: The need to serialize/deserialize JSON messages caused overhead.
• Limited Interoperability: Sharing complex data structures was tricky, leading to limitations in functionality.

What’s New in React Native’s Architecture?

The new architecture of React Native ditches the Bridge in favor of a bridge-less design, providing a direct connection between the JS and Native layers. It introduces:

1. Fabric Renderer: A modern rendering pipeline for better UI responsiveness.
2. Turbo Modules: A new way to load native modules synchronously and efficiently.
3. JSI (JavaScript Interface): Allows JavaScript to directly call native functions, bypassing the Bridge.

These updates make React Native faster, more reliable, and scalable for larger applications.

Why Did React Native Change?

React Native’s old architecture served its purpose well for years, but as apps grew more complex, so did the challenges:

1. Performance Issues: Apps with heavy animations or data processing suffered from lag due to the Bridge’s asynchronous nature.
2. Developer Experience: Debugging inter-thread communication and handling large JSON messages became increasingly cumbersome.
3. Future-Proofing: To compete with newer frameworks like Flutter, React Native needed to innovate.

The new architecture addresses these challenges by reducing overhead and providing a more direct and seamless integration between JS and Native code.

When Should You Transition to the New Architecture?

The new architecture is already available, but transitioning isn’t mandatory yet. Here’s a breakdown of when you should consider adopting it:

1. If Performance Is a Concern: Apps with high-performance requirements (e.g., gaming, AR) will benefit the most.
2. For New Apps: Starting fresh? Adopt the new architecture to future-proof your app.
3. When Upgrading Dependencies: If your existing app heavily relies on native modules, upgrading to TurboModules can simplify your development process.

Conclusion

Understanding the “old” is key to appreciating the “new.” React Native’s new architecture is more than just an update; it’s a complete reimagining of how JS and Native layers interact. If you’re building or maintaining React Native apps, now is the perfect time to explore these changes and take your apps to the next level.

Want to see it in action? Check out the official React Native documentation and start experimenting today!