state management , Rxjava, Kotlin, Uikit, Gradle, React Native, Flutter, Swift, Dependency Injection, Logging, SwiftUI, Android lifecycle, Flow, Jetpack, Compose, Release and rollout pipeline, Mobile observability, Kotlin coroutines, KMP, Network stack, Threading and concurrency, CI/CD, Apple toolchain and release process, Persistence layer, Crash reporting, Testing strategy, Observability, Swift concurrency model