src/
├── components/    # Reusable UI components
├── screens/       # Screen-level components
├── navigation/    # React Navigation config
├── services/      # API, storage, native modules
├── hooks/         # Custom hooks
├── store/         # State management
├── utils/         # Helpers
└── types/         # TypeScript types

// Stack + Tab pattern
const RootStack = createNativeStackNavigator();
const MainTabs = createBottomTabNavigator();

function App() {
  return (
    <NavigationContainer>
      <RootStack.Navigator>
        <RootStack.Screen name="Main" component={MainTabs} />
        <RootStack.Screen name="Details" component={DetailsScreen} />
      </RootStack.Navigator>
    </NavigationContainer>
  );
}

// NativeModule.ts
import { TurboModuleRegistry } from 'react-native';
export default TurboModuleRegistry.getEnforcing('MyCustomModule');