Alex Chen

Hilt simplifies dependency injection in Android with compile-time code generation. I annotate Application class with @HiltAndroidApp and activities/fragments with @AndroidEntryPoint. Modules marked with @Module and @InstallIn define how to provide dep

Retrofit simplifies HTTP networking with type-safe API definitions. I define service interfaces with annotated methods—@GET, @POST, @PUT, @DELETE. Path parameters use @Path, query params use @Query, and request bodies use @Body. Retrofit converts resp

Room provides an abstraction layer over SQLite for compile-time verified database access. I define entities with @Entity annotation, specifying table structure and relationships. DAOs (Data Access Objects) marked with @Dao contain query methods using

MVVM separates concerns in Android apps—Model holds data, View displays UI, ViewModel mediates with business logic. ViewModels survive configuration changes, preventing data loss during rotation. I use ViewModel class with viewModelScope for coroutine

Kotlin coroutines provide structured concurrency for asynchronous programming. I use suspend functions to mark async code, and launch or async to start coroutines. viewModelScope and lifecycleScope tie coroutines to component lifecycles, cancelling au

Jetpack Compose revolutionizes Android UI development with declarative, Kotlin-first approach. Composable functions annotated with @Composable describe UI based on state. The runtime automatically updates UI when state changes using remember and mutab