macos-app-performancelisted

# macos-app-performance Measures how a macOS app performs (hangs, launch time, CPU, memory, energy) and judges every number against the thresholds Apple publishes, so you know what to fix first. Works on any running app, uses Instruments where Xcode is installed, and can keep a baseline to catch regressions between releases. Everything here is macOS-applicable and sourced from Apple's documentation; where Apple's guidance is iOS-only, this skill says so instead of borrowing it, and where Apple's own material is archived or does not affirm macOS support, the reference covering it says so. ## Step 1 — establish the subject A running app is named by name, pid, or bundle path. Detect a project in the working directory, because it decides what can be measured: ```bash find . -maxdepth 1 \( -name Package.swift -o -name '*.xcodeproj' -o -name '*.xcworkspace' \) # Swift / Xcode (a bare glob aborts under zsh) [ -f src-tauri/tauri.conf.json ] && echo tauri [ -f package.json ] && grep -q '"electron"' package.json && echo electron ``` **The app is usually not one process.** Tauri, Electron, and anything with XPC helpers or a WebKit content process spread work across several, and the one doing the work is rarely the one named on the bundle. Enumerate with `pgrep -fl <app-name>` and attribute every number to a named process. **Measure a release build**, with the accuracy settings Apple prescribes for performance work — see [references/measurement.md](references/measurement.md). If