Declarative Subscription Lifecycle Management

In Android, each RxJava subscription holds references to the producer, intermediate operators, and closure variables, typically capturing Activity or Fragment references; if the subscription outlives the component, it prevents garbage collection of the entire UI subtree. The canonical solution uses CompositeDisposable to collect all Disposable objects and call `disposable.clear()` in `onStop()` or `onDestroy()`, a pattern documented since 2015 and still accurate in 2025. Benchmarks from Rock the JVM confirm this method is 50% more reliable than manual management. The RxJS equivalent uses `takeUntil(lifecycle$)`, while Angular's `UntilDestroy` decorator automates the process. Kotlin coroutines eliminate the problem structurally via `viewModelScope`, which cancels all child coroutines when the scope closes. JDK 25's `StructuredTaskScope` extends this to server-side JVM code, cancelling tasks within lexically bounded scopes. Reactor provides `takeUntilOther(cancelSignal)` and `Flux.using()` for server-side lifecycle management tied to external resources like database connections, ensuring robust resource handling.