Both Hilt and Koin can provide dependencies. I prefer Hilt for a large Android application because missing bindings and incompatible scopes fail during compilation rather than after a user launches the affected path.
@Module
@InstallIn(SingletonComponent::class)
object StorageModule {
@Provides
@Singleton
fun database(@ApplicationContext context: Context): AppDatabase =
Room.databaseBuilder(context, AppDatabase::class.java, "app.db").build()
}
Hilt also integrates with Android lifecycles and ViewModels. Its cost is code generation, build configuration, and less runtime flexibility.
Koin's Kotlin DSL is lightweight and easy to read. Runtime resolution can be productive for smaller applications, prototypes, or teams that value dynamic modules. Its graph errors appear later unless tests exercise startup comprehensively.
Do not inject every data class and pure function. Use constructors directly where ownership is obvious. DI is useful at replaceable boundaries: repositories, platform managers, databases, analytics, and dispatchers.
Scopes should match resource lifetimes. A database is application-wide; a screen coordinator may belong to a ViewModel. Incorrect singleton scope can leak mutable user state.
The decision is less about syntax and more about when you want invalid graphs to fail. In production infrastructure-heavy apps, build-time feedback is worth additional setup.