GC pauses cause stop-the-world event-loop stalls

Garbage collection causes periodic stop-the-world hiccups that stall the event loop. Memory usage charts don't reveal GC pause timing or frequency. Correlation between event-loop lag spikes and major GC events indicates GC is the root cause.

Track GC pause time and frequency using runtime metrics or diagnostics tooling. Monitor major GC frequency, old space growth, and allocation rate. Correlate GC events with event-loop lag spikes to confirm GC as cause.