Performance Optimization
Performance optimization patterns and best practices for React/React Native applications.
Quick Reference
| Category | Key Optimization | When to Use |
|---|---|---|
| Concurrent Requests | Limit to 3-5, use executeBatched | Multiple API calls, network-heavy operations |
| Bridge Optimization | Minimize crossings, batch data | React Native bridge overhead, iOS/Android |
| List Rendering | FlashList, windowSize={5}, content-visibility | Lists with 100+ items |
| Memoization | memo, useMemo, useCallback | Expensive computations, prevent re-renders |
| Heavy Operations | InteractionManager, setTimeout | UI blocking operations |
Critical Performance Rules
❌ FORBIDDEN: Too Many Concurrent Requests
typescript
// ❌ BAD - Can freeze UI with 15+ requests const requests = items.map(item => fetchData(item)); await Promise.all(requests);
✅ CORRECT: Batched Execution with Concurrency Limit
typescript
async function executeBatched<T>(
tasks: Array<() => Promise<T>>,
concurrency = 3,
): Promise<Array<PromiseSettledResult<T>>> {
const results: Array<PromiseSettledResult<T>> = [];
for (let i = 0; i < tasks.length; i += concurrency) {
const batch = tasks.slice(i, i + concurrency);
const batchResults = await Promise.allSettled(
batch.map((task) => task()),
);
results.push(...batchResults);
}
return results;
}
const tasks = items.map(item => () => fetchData(item));
await executeBatched(tasks, 3); // Max 3 concurrent
🚨 Built-in Optimizations
Already Optimized - NO ACTION NEEDED:
| Component | Optimization | Details |
|---|---|---|
ListView | windowSize={5} | Auto-limits visible items |
Tabs | contentVisibility: 'hidden' | Hides inactive tabs |
Dialog | contentVisibility: 'hidden' | Hides when closed |
Detailed Guide
For comprehensive performance optimization strategies, see performance.md.
Topics covered:
- •Concurrent request control
- •React Native bridge optimization
- •Heavy operations offloading
- •List rendering (windowSize, FlashList, content-visibility)
- •Memoization & callbacks
- •State updates optimization
- •Image optimization
- •Async operations & race conditions
- •Real-world iOS AppHang case study
Related Skills
- •
/coding-patterns- General coding patterns and conventions - •
/sentry-analysis- Sentry error analysis (includes performance issues) - •
/react-best-practices- React/React Native optimizations