Android Architecture

MVVM + Clean Architecture with Unidirectional Data Flow. These patterns prevent the most common structural mistakes AI agents make when building Android apps.

The three layers — strict separation

Presentation (UI)          →  only depends on Domain
    ViewModel              →  calls UseCases, exposes UiState + Events
    Composables            →  observes ViewModel, sends user actions

Domain (Business Logic)    →  pure Kotlin, zero Android dependencies
    UseCases               →  orchestrate one business operation
    Repository interfaces  →  contracts, implemented in Data layer
    Domain models          →  pure data classes