React Native Interview Questions

• React Native vs Expo? Expo = managed workflow with pre-built native modules, OTA updates, EAS build. Bare RN = full control but manual native setup. Start with Expo; eject only if needed

• How does the bridge work (new architecture)? Old: JS ↔ Bridge (async JSON serialization) ↔ Native. New Architecture (JSI): JS calls native synchronously via C++ interface — no serialization, lower latency

• How to optimize list performance? Use FlatList (not ScrollView for long lists), memo+keyExtractor, getItemLayout for fixed-height items, windowSize/maxToRenderPerBatch props, avoid anonymous render functions

• How to handle keyboard covering inputs? KeyboardAvoidingView with behavior="padding" (iOS) or "height" (Android). Or KeyboardAwareScrollView from react-native-keyboard-aware-scroll-view

• StyleSheet.create vs plain objects? StyleSheet.create validates styles in dev, sends IDs not objects across bridge, enables native-side caching — always prefer it

• How to run code only on iOS or Android? Platform.OS === "ios", Platform.select({ios: ..., android: ...}), or file extensions: Component.ios.tsx / Component.android.tsx

• State management options? Same as React: Zustand (lightweight), Redux Toolkit (complex global state), React Query / TanStack Query for server state + React Context for simple sharing