React Native Performance Audit

Instructions

Measure before optimizing. The cheapest wins almost always come from fixing re-renders and list configuration, not from native code changes.

1. Hermes Sampling Profiler

Hermes ships a built-in sampler. Record a trace from a dev build:

import { startSamplingProfiler, stopSamplingProfiler } from 'react-native/Libraries/Utilities/HMRClient';
// In dev, connect via Chrome DevTools -> "Performance" tab on the Hermes target.

Or via the command line: