Native App Performance

**Judgement:** A strong, specialized skill for CLI-only performance profiling of native macOS/iOS apps using Time Profiler traces. It is narrow in scope but well-aligned with real-world Apple developer workflows, especially where Instruments UI is unavailable or undesirable. **Strengths:** - Provides a complete headless pipeline: record with `xcrun xctrace`, extract samples, symbolicate using runtime load addresses, and rank hotspots. - Good fit for automation and CI, where reproducible performance analysis and regression detection are needed. - Emphasizes practical gotchas (ASLR, matching binary builds, correct capture scenarios), which are common sources of error in profiling. **Risks / Limitations:** - Apple-platform only; requires macOS with Xcode command-line tools and familiarity with terminal usage. - Focused on CPU Time Profiler; does not appear to cover other Instruments templates (memory, energy, etc.). - Accuracy of results depends heavily on the user providing the correct binary, load address, and meaningful profiling scenario; misconfiguration can lead to misleading conclusions. - Trace data can include sensitive code symbols and call stacks, so users must handle artifacts with appropriate privacy/security practices. **Recommended scenarios:** - Native macOS/iOS developers wanting to profile performance or hotspots via CLI instead of opening Instruments. - Teams integrating performance profiling into CI or automated scripts where a GUI is not available. - Users who provide `.trace` files and want help extracting, symbolizing, and interpreting hotspots to guide code-level optimizations.