swiftui-performance-audit

What This Skill Does

The swiftui-performance-audit skill is an advanced diagnostic toolkit designed to help developers identify, analyze, and resolve performance bottlenecks within SwiftUI applications. Rather than offering generic advice, this skill follows a structured workflow: it initiates a code-first analysis to detect common architectural anti-patterns—such as view invalidation storms, unstable identities in lists, and expensive computations within the body property—before guiding the user through high-fidelity diagnostic procedures using Apple's Instruments. By bridging the gap between static code analysis and runtime profiling, it ensures that performance optimizations are data-driven and effectively address the root causes of jank, high CPU usage, or layout thrash.

Installation

To integrate this skill into your environment, run the following command in your terminal: clawhub install openclaw/skills/skills/steipete/swiftui-performance-audit

Use Cases

• Janky Scrolling: Pinpointing why a List or LazyVStack stutters during navigation or data updates.
• Layout Thrash: Investigating complex view hierarchies where GeometryReader or deep preference chains trigger excessive recalculations.
• High CPU/Memory Usage: Identifying inefficient state management or improperly scoped observables that trigger redundant view updates.
• Animations: Debugging expensive view trees that suffer from performance degradation when performing implicit animations.
• Image Rendering: Optimizing large image assets that lack proper downsampling or caching, causing main-thread blocking.

Example Prompts

1. "My SwiftUI list stutters significantly when scrolling through 500 items. Can you help me analyze my row view code to see if I'm causing view invalidation storms?"
2. "I'm seeing high CPU usage whenever my @Observable model updates. Here is my current state setup—can you tell me if I'm holding state too high in the hierarchy?"
3. "Instruments shows a massive 'Time Profile' hit in my body property for a date formatter. How can I refactor this to be more performant?"

Tips & Limitations

• Always Profile First: While code reviews catch obvious smells, runtime data is the ultimate truth. If the performance issue persists after refactoring, use the guide to generate an Instruments trace.
• Scope Matters: This skill thrives when you provide context. Sharing a snippet of the problematic view and its corresponding data model allows for much more accurate remediation.
• Contextual Awareness: Remember that this skill is optimized for SwiftUI specifically. If your performance bottleneck is in legacy UIKit or custom C++ layers, you may need additional debugging tools outside this scope.