compose-multiplatform-patterns

Use a single immutable data class for screen state exposed as StateFlow from the ViewModel, and collect it in Compose with collectAsStateWithLifecycle. Update state via MutableStateFlow.update with copy operations rather than mutableStateOf.

Define routes as @Serializable objects or data classes and register them with composable<Route> in a NavHost using Compose Navigation 2.8+. Retrieve arguments with backStackEntry.toRoute<Route>() and navigate by passing route instances to navController.navigate.

Yes, use expect/actual declarations for platform composables. Declare an expect composable in commonMain and provide actual implementations in androidMain and iosMain, such as a PlatformStatusBar that uses system UI controllers on Android and UIKit interop on iOS.

Excessive recomposition usually comes from unstable parameter types, new object allocations in composable parameters, or reading state too early. Mark models @Immutable or @Stable, wrap derived values in remember with derivedStateOf, and provide stable keys in lazy lists.

No, passing NavController deep into composables is an anti-pattern. Pass navigation lambda callbacks or a single event sink function instead, which keeps composables stateless, previewable, and easy to test.