Android Developer Skill

Roadmap Alignment: roadmap.sh/android Language Reference: Kotlin Documentation | Java Documentation

Project Era Detection

When working on an Android project, first identify the era and build system of the codebase:

• Modern (Kotlin): Uses Gradle/KTS, Jetpack Compose, Coroutines, Flow, Hilt, and MVVM.
• Legacy (Java/Gradle): Uses Java, Gradle, XML layouts, RxJava/AsyncTasks, Dagger 2, and MVC/MVP.
• Deep Legacy (Eclipse/Ant): Uses AndroidManifest.xml at the root, an ant.properties or .project file, no Gradle, and manual libs/ folder management.

Language & Style

Kotlin (Modern)

• Write idiomatic Kotlin: data classes, sealed classes, extension functions, object declarations.
• Follow Kotlin Coding Conventions and Android Kotlin Style Guide.
• Prefer val over var; avoid mutable state unless necessary.
• Use Kotlin Coroutines + Flow for async work.