Performance Profiling

Overview

iOS app performance problems fall into distinct categories, each with a specific diagnosis tool. This skill helps you choose the right tool, use it effectively, and interpret results correctly under pressure.

Core principle: Measure before optimizing. Guessing about performance wastes more time than profiling.

Requires: Xcode 15+, iOS 14+ Related skills: axiom-swiftui-performance (SwiftUI-specific profiling with Instruments 26), axiom-memory-debugging (memory leak diagnosis)

When to Use Performance Profiling

Use this skill when

• ✅ App feels slow (UI lags, loads take 5+ seconds)
• ✅ Memory grows over time (Xcode shows increasing memory usage)
• ✅ Battery drains fast (device gets hot, battery depletes in hours)
• ✅ You want to profile proactively (before users complain)
• ✅ You're unsure which Instruments tool to use