kotlin

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

LiveData transformations create derived data streams reactively. Transformations.map() converts values—like mapping User to username string. Transformations.switchMap() switches LiveData sources based on input, enabling dynamic queries. MediatorLiveDa

Android performance optimization ensures smooth 60fps UI and efficient resource usage. I use Android Profiler to monitor CPU, memory, network, and energy. Layout Inspector identifies overdraw and deep view hierarchies. Systrace captures system-level t

App Widgets display app content on the home screen. I extend AppWidgetProvider, a BroadcastReceiver subclass handling widget lifecycle. onUpdate() refreshes widget UI, onEnabled() initializes on first widget added, onDisabled() cleans up when last rem

Unit testing verifies individual components in isolation. I use JUnit 5 or JUnit 4 as the test framework with @Test annotations. MockK provides Kotlin-friendly mocking—mockk<T>() creates mocks, every { } stubs behavior, verify { } confirms calls

Notification channels give users granular control over notification types on Android 8+. I create channels with unique IDs, names, and importance levels. Channels group related notifications—messages, reminders, promotions. Users control vibration, so

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

Navigation Component provides consistent navigation with type-safe argument passing. I define navigation graph in XML with destinations and actions. NavController handles navigation with navigate() and popBackStack(). Safe Args plugin generates type-s

Deep links open specific app content from external sources. I configure intent filters in AndroidManifest with URL schemes—http, https, or custom. App Links verify ownership via assetlinks.json on your domain, providing seamless no-dialog opening. Int

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

CameraX simplifies camera implementation with consistent behavior across devices. I bind use cases—Preview, ImageCapture, ImageAnalysis, VideoCapture—to lifecycle. ProcessCameraProvider manages camera instances. Preview displays viewfinder, ImageCaptu

BiometricPrompt provides secure authentication via fingerprint, face, or iris. I create BiometricPrompt with callback handling success, error, and failure. PromptInfo configures title, subtitle, description, and allowed authenticators. Negative button