Performance Profiling Use this skill to diagnose Apple app performance issues systematically, pick the right profiling workflow, apply targeted fixes, and verify the change with real measurements. Decision Tree Choose the reference file before changing code: Quick Reference | Problem | Instrument / Tool | Key Metric | Reference | | --- | --- | --- | --- | | UI hangs over 250 ms | Time Profiler + Hangs | Hang duration, main thread stack | | | High CPU usage | Time Profiler | CPU percent by function, call tree weight | | | Memory leak | Leaks + Memory Graph | Leaked bytes, retain cycle paths |…