# Swiftui Performance

Profile, diagnose, and remediate SwiftUI runtime performance using code review...

- Repository: https://github.com/dpearson2699/swift-ios-skills (1266 stars)
- Category: Design
- License: see repository
- Last updated: 2026-07-31
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add dpearson2699/swift-ios-skills --skill swiftui-performance -g -a claude-code -y`
Codex: `npx skills add dpearson2699/swift-ios-skills --skill swiftui-performance -g -a codex -y`
Cursor: `npx skills add dpearson2699/swift-ios-skills --skill swiftui-performance -g -a cursor -y`
Gemini CLI: `npx skills add dpearson2699/swift-ios-skills --skill swiftui-performance -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add dpearson2699/swift-ios-skills`

## Description

Profile, diagnose, and remediate SwiftUI runtime performance using code review, Instruments, and repeatable measurements. Use when a SwiftUI screen renders slowly, scrolling or animations hitch, view bodies update excessively, list identity churns, layout work spikes, or broad Observation dependencies raise CPU cost. Covers evidence-based triage, SwiftUI Instruments lanes, lazy-container guardrails, state lifetime, and before/after verification.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# SwiftUI Performance

Audit SwiftUI view performance from a reproducible symptom to measured
remediation. Route animation design to `swiftui-animation`, production telemetry
to `metrickit`, ownership/leak analysis to `ios-memgraph-analysis`, navigation
behavior to `swiftui-navigation`, state architecture to `swiftui-patterns`, and
layout construction to `swiftui-layout-components`.

## Contents

- [Workflow Decision Tree](#workflow-decision-tree)
- [1. Code-First Review](#1-code-first-review)
- [2. Guide the User to Profile](#2-guide-the-user-to-profile)
- [3. Analyze and Diagnose](#3-analyze-and-diagnose)
- [4. Remediate](#4-remediate)
- [Common Code Smells (and Fixes)](#common-code-smells-and-fixes)
- [5. Verify](#5-verify)
- [Outputs](#outputs)
- [Instruments Profiling](#instruments-profiling)
- [Identity and Lifetime](#identity-and-lifetime)
- [Lazy Loading Patterns](#lazy-loading-patterns)
- [State and Observation Optimization](#state-and-observation-optimization)
- [Common Mistakes](#common-mistakes)
- [Review Checklist](#review-checklist)
- [References](#references)

## Workflow Decision Tree

- Code supplied: review it first and label findings as hypotheses.
- Symptoms only: collect the smallest relevant view, data flow, reproduction,
  device, OS, and build configuration.
- Inconclusive review: collect a trace or lane screenshots before prescribing a
  broad refactor.

Use this triage list for both code and trace analysis:

- Broad state dependencies or invalidation storms
- Unstable list identity or root conditional swapping
- Formatting, sorting, decoding, or synchronous I/O in `body`
- Layout/geometry feedback loops and oversized images
- Implicit animation applied to a large hierarchy

## 1. Code-First Review

Map each suspect from the triage list to exact code. Report likely causes with
code references, but label them code-backed hypotheses until a trace confirms
cost. Propose a minimal repro or measurement when evidence is missing.

The rest: https://github.com/dpearson2699/swift-ios-skills/blob/HEAD/skills/swiftui-performance/SKILL.md