The Problem (Old Architecture)

Think of the old React Native like two people (JavaScript and Native/phone) talking through a walkie-talkie (called "the Bridge"). Every message had to be converted to text, sent over, then converted back. This was slow and caused issues like:

• UI flickering/jumping — e.g., a tooltip would briefly appear in the wrong place before snapping to the correct position
• Sluggish updates — when lots of things changed at once, the UI felt laggy
• Couldn't handle heavy data — processing things like camera frames (gigabytes per second) was painful through serialization

The Fix (New Architecture): 3 Big Wins

1. Synchronous Layout (no more visual jumps)

Old way: You measure a view's position → send it over the bridge → update. Between those steps, the user sees a glitchy intermediate frame.

New way: Measure and update happen in one step, so users never see the "jump." Think of it like placing a tooltip — now it appears in the right spot instantly instead of flickering.

2. React 18 Concurrent Features

• Automatic batching — if 100 state updates fire rapidly (like dragging a slider), React groups them together instead of rendering each one. Result: smoother UI.
• Transitions — you can tell React "this update is low priority, don't block the UI for it." So the slider stays smooth while tiles render in the background.

3. JSI (JavaScript Interface) — direct communication

Instead of the walkie-talkie (bridge), JS and Native now share the same memory — like two people in the same room pointing at the same objects. No more converting data back and forth. This is why libraries like VisionCamera can process ~2GB/sec of camera data in real-time now.

Should You Care?

• As of React Native 0.76+, the New Architecture is on by default
• You don't need to do anything to enable it for new projects
• Your existing code won't magically get faster — you need to actually use the new APIs (useLayoutEffect, useTransition, etc.) to see benefits
• It's the future of RN, so it's worth learning for your bootcamp curriculum