The Modern Guide to Android SDK Development: Architecture & API Design (Part 1 of 3)

A senior engineer's guide to building consumer-grade Android SDKs, using an AnalyticsKit example. Covers seven core principles: designing the API before implementation, choosing between singleton and factory entry point patterns (with thread-safe hybrid approach), structuring configuration as a validated data contract, exposing reactive state via Kotlin StateFlow, controlling visibility with Kotlin's internal modifier and explicitApi(), isolating dependencies and managing transitive permissions, and ensuring thread safety with SupervisorJob and coroutine scopes. Includes concrete Kotlin code for each principle and discusses tradeoffs like data class binary compatibility and when to use StateFlow vs SharedFlow.