performance-profiling

What problem does it solve?

This Skill helps developers systematically identify the root cause of app performance issues such as UI lag, memory growth, and excessive battery drain. It prevents wasted time optimizing the wrong areas or misinterpreting complex profiling results.

Core Features & Use Cases

• Instruments Decision Tree: Guides you to the correct Xcode Instruments tool (Time Profiler, Allocations, Core Data, Energy Impact) based on the specific performance symptom.
• Deep Dive Workflows: Step-by-step instructions for effectively using Time Profiler, Allocations, and Core Data instruments to diagnose bottlenecks.
• Pressure Scenario Guidance: Provides strategies for interpreting profiling results correctly under common development pressures, preventing misdiagnosis and ensuring targeted fixes.
• Use Case: When your app feels slow or lags, use the Time Profiler workflow to identify CPU-intensive functions, ensuring you optimize the actual bottleneck, not just a caller function.

Quick Start

To find CPU bottlenecks, launch Instruments, select "Time Profiler", record the slow interaction, then analyze the "Heaviest Stack Trace" to identify functions with high "Self Time".