android-clean-architecture

Split the project into app, core, domain, data, and presentation modules with dependencies pointing inward. The domain module holds UseCases, models, and repository interfaces in pure Kotlin, while data implements repositories and presentation holds ViewModels and screens.

Create a class with an operator fun invoke that delegates to a repository, returning Result<T> for one-shot operations or Flow<T> for reactive streams. Inject the repository interface through the constructor so the UseCase stays framework-free and testable.

Koin works in Kotlin Multiplatform shared code using module definitions with single and factory declarations. Hilt is Android-only, using @Module, @Binds, and @HiltViewModel annotations, so choose Koin when sharing DI across platforms.

Yes, SQLDelight defines tables and queries in .sq files for shared local storage, and Ktor's HttpClient with ContentNegotiation handles network calls in commonMain. Repository implementations coordinate both DataSources behind domain interfaces.

Framework dependencies in domain couple business logic to the platform, breaking testability and KMP sharing. Keep domain models as plain data classes and repository interfaces pure Kotlin, mapping entities and DTOs at the data layer boundary.

Common mistakes include exposing database entities to the UI, putting business logic in ViewModels instead of UseCases, using GlobalScope instead of viewModelScope, and creating circular module dependencies. Fat repositories should be split into focused DataSources.