Performance Optimization Techniques

React Native Performance: #

Optimize list rendering with FlatList and proper keyExtractor. Use getItemLayout for consistent-height items to skip measurement. Implement windowSize, initialNumToRender, and maxToRenderPerBatch for large lists. Prevent unnecessary re-renders with React.memo for expensive components. Use useCallback for function props that trigger re-renders. Implement useMemo for expensive calculations. Optimize images with proper sizes, formats (WebP), and caching. Use FastImage for better image performance. Implement lazy loading for off-screen content. Use InteractionManager to defer expensive operations until after animations complete.

App Bundle Size & Startup: #

Reduce bundle size by removing unused dependencies. Use import from specific paths instead of barrel imports to enable tree-shaking. Analyze bundle with npx react-native-bundle-visualizer. Implement code splitting for large features. Defer non-critical imports with React.lazy and Suspense. Optimize images during build: compress, resize, and convert to optimal formats. Use Hermes JavaScript engine for faster startup and lower memory. Enable RAM bundles for faster startup on Android. Implement splash screen with expo-splash-screen. Preload critical data during splash. Use persistent caching with AsyncStorage for instant content on subsequent launches.

Network & Data Optimization: #

Minimize API calls with batching and aggregation. Implement request deduplication to avoid duplicate in-flight requests. Use pagination for large datasets: limit results, implement infinite scroll. Cache API responses with React Query or custom caching layer. Implement optimistic updates for instant UI feedback. Use GraphQL for precise data fetching (if applicable). Compress API payloads with gzip. Implement offline support with service workers or offline-first architecture. Prefetch likely-needed data: next page, related content. Use CDN for static assets and media. Implement progressive image loading: placeholder → low-res → high-res.