Kotlin Concurrency Expert

This one tackles the messy reality of Kotlin coroutines in Android: ANRs from blocking the main thread, memory leaks from GlobalScope, zombie coroutines outliving their ViewModels, and the deprecated launchWhenStarted pattern that still haunts older codebases. It pushes you toward dispatcher injection for testability, repeatOnLifecycle for safe Flow collection, and proper CancellationException handling. The workflow is triage first, then apply the smallest fix that gets you to structured concurrency without rewriting everything. If you're debugging why your app freezes on rotation or why background work never cancels, this covers the common patterns and anti-patterns with specific before-and-after examples.