performance

1# Performance Skills
2 
3Diagnose and fix performance problems, from system-level profiling to SwiftUI render behavior.
4 
5## When This Skill Activates
6 
7Use this skill when the user:
8- Reports the app is **slow, janky, or hanging**
9- Wants to profile with **Instruments** (Time Profiler, Allocations, Hangs)
10- Is investigating **memory issues, slow launches, or energy drain**
11- Sees SwiftUI views **re-rendering too often** or slow `body` evaluations
12- Asks about **view identity** problems or `_printChanges()`
13 
14## Available Skills
15 
16Paths are relative to THIS file's directory — skills run with cwd set to the
17user's project, so resolve each path from this SKILL.md's own location.
18 
19| Skill | Read | Covers |
20|-------|------|--------|
21| profiling | `profiling/SKILL.md` | Instruments workflows; hangs, memory, slow launch, energy diagnosis |
22| swiftui-debugging | `swiftui-debugging/SKILL.md` | Unnecessary re-renders, view identity, slow body evaluations |
23 
24## How to Route
25 
261. Match the request to a row above — system-level symptoms → profiling; SwiftUI render symptoms → swiftui-debugging.
272. Read that SKILL.md (relative to this file) plus any reference files it lists.
283. Apply the guidance to the user's code.