Mobile App Performance Optimization: From 60fps to Buttery Smooth

Performance Metrics That Matter

Rendering Optimization

FlatList Optimization

For long lists, proper FlatList configuration is critical for smooth scrolling.

<FlatList
  data={items}
  renderItem={renderItem}
  keyExtractor={item => item.id}
  getItemLayout={(data, index) => ({
    length: ITEM_HEIGHT,
    offset: ITEM_HEIGHT * index,
    index
  })}
  removeClippedSubviews={true}
  maxToRenderPerBatch={10}
  windowSize={5}
/>

Image Optimization

• Use WebP format for 25-35% smaller files
• Implement progressive loading with blur placeholders
• Cache aggressively with proper invalidation
• Resize images for different screen densities

Memory Management

// Avoid memory leaks: always clean up subscriptions
useEffect(() => {
  const subscription = AppState.addEventListener('change', handler);
  return () => subscription.remove();
}, []);

// Use lazy loading for heavy components
const HeavyComponent = React.lazy(() => import('./HeavyComponent'));

Battery Efficiency

• Batch network requests instead of many small ones
• Use background fetch instead of continuous polling
• Implement proper location update strategies
• Minimize sensor usage when not needed

Profiling Tools

• React Native: Flipper, React DevTools Profiler
• Flutter: DevTools, Timeline view
• iOS: Instruments, Xcode Energy Log
• Android: Android Studio Profiler, Systrace