Rendering Performance in React Native

Understanding React Native's rendering cycle is key to building smooth, responsive apps.

Render Cycle: React Native batches updates and schedules renders. Avoid synchronous heavy work during render. Use useMemo and useCallback strategically, but don't overuse — profile first.

InteractionManager: Defer non-critical work until interactions complete. Use InteractionManager.runAfterInteractions() for API calls, analytics, and heavy computations after animations.

Heavy Screens: Break complex screens into smaller components. Use React.memo for expensive components. Implement virtual scrolling for long lists. Lazy load below-the-fold content.

Complex UIs: Simplify component trees. Avoid deeply nested views. Use absolute positioning sparingly. Minimize layout calculations.

Animation Performance: Use useNativeDriver: true for transform and opacity animations. Avoid animating layout properties. Use Animated API for complex sequences. Consider react-native-reanimated for advanced animations.

Re-render Optimization: Identify unnecessary re-renders with React DevTools Profiler. Use React.memo with custom comparison functions. Split components to isolate state changes.

List Performance: Use keyExtractor with stable IDs. Implement getItemLayout for known heights. Set appropriate windowSize and initialNumToRender. Use FlashList for better performance than FlatList.

Profile on real devices. Measure frame rates. Aim for consistent 60fps during interactions.