iOS Performance Profiling

Purpose

Use this skill to choose the right profiling workflow, gather evidence, interpret performance signals, and recommend validation before claiming that an optimization worked.

This skill is a profiling router and evidence workflow. It should not replace more specific skills for launch performance, SwiftUI performance, Swift Concurrency performance, perceived performance, or Swift runtime costs.

When to use this skill

Use this skill when the task involves:

• choosing an Instruments template or profiling workflow;
• interpreting traces, screenshots, XCTest metrics, MetricKit payloads, Organizer data, logs, or signposts;
• diagnosing hangs, animation hitches, CPU spikes, memory growth, leaks, disk I/O, network latency, power usage, or production regressions;
• designing a before/after measurement plan;
• adding signposts or performance tests;
• checking whether a proposed optimization is supported by evidence.