react-native-dev

Use Expo Router file-based navigation where files in the app/ directory map directly to routes. Define a root Stack in app/_layout.tsx, create tab groups in app/(tabs)/_layout.tsx, and use kebab-case filenames for route files.

Use useState or useReducer for local UI state, Zustand or Jotai for shared app state, and React Query for server and async data. Avoid Redux for new projects due to boilerplate and Context for high-frequency updates.

FlashList from Shopify recycles off-screen views and is preferred over FlatList, which lacks view recycling and causes scroll jank on long lists. Always provide estimatedItemSize and wrap list items in memo.

Yes, use Reanimated 3 and only animate transform and opacity properties, which are GPU-composited. Animating width, height, or margin forces layout recalculation on every frame and drops frames.

Use jest-expo with React Native Testing Library for unit and component tests, querying by role or label rather than test IDs. For end-to-end flows like login, use Maestro with YAML flow definitions.

Expo Go covers most cases, but switch to a custom dev client via eas build when using local Expo modules, Apple targets like widgets, or third-party native libraries not bundled in Expo Go.