Question 1

How do I manage UI state in Compose Multiplatform ViewModels?

Accepted Answer

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() to keep emissions atomic and testable.

Question 2

How to implement type-safe navigation in Jetpack Compose?

Accepted Answer

Define routes as @Serializable objects or data classes and register them with composable in a NavHost using Compose Navigation 2.8+. Retrieve arguments with backStackEntry.toRoute() instead of parsing string routes.

Question 3

Does Compose Multiplatform support platform-specific UI on iOS and Android?

Accepted Answer

Yes, use expect/actual declarations for composables that need platform behavior, such as status bar styling. The commonMain expect composable is implemented per platform in androidMain and iosMain, with iOS handled via UIKit interop or Info.plist.

Question 4

Why does my composable recompose too often?

Accepted Answer

Frequent recomposition usually comes from unstable parameter types, new object or lambda allocations in composable parameters, or reading state eagerly. Mark models @Immutable, use remember and derivedStateOf, and provide stable keys in lazy lists.

Question 5

When should I use an event sink instead of callback lambdas in Compose?

Accepted Answer

Use a sealed interface event sink when a screen has many user actions, so the composable takes a single onEvent lambda instead of numerous callbacks. The ViewModel handles events in a when block, keeping the composable stateless and easy to preview.

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