swiftui-performance-audit

The SwiftUI Performance Audit skill provides a comprehensive diagnostic framework for mobile engineers to identify and resolve performance bottlenecks in SwiftUI-based applications. Whether you are dealing with choppy animations, sluggish list scrolling, excessive CPU/memory footprints, or complex layout thrash, this skill helps you move from symptoms to actionable, data-driven remediation.

Designed for developers and technical leads, this agent acts as a specialized consultant that understands the nuances of SwiftUI’s dependency graph, body evaluation cycles, and the main run loop. It excels at parsing source code to catch common performance antipatterns such as expensive formatting within view bodies, unstable identity in lists, and broad state invalidation storms. When static analysis is insufficient, it provides expert guidance on using Xcode Instruments, specifically the SwiftUI template, to isolate hitches and long view body updates.

• Performs in-depth code reviews to identify view invalidation storms, @Observable data misuse, and inefficient layout logic.

• Provides concrete refactoring strategies to stabilize view identity in ForEach and List components.

• Instructs users on how to capture and interpret SwiftUI timelines, Time Profiler call trees, and Hangs instrument data to correlate UI hitches with specific code paths.

• Advises on moving heavy computations, image decoding, and data sorting out of the main thread and body scope to improve frame delivery.

• Offers guidance on best practices for efficient state management, including the use of granular view models, @State placement, and Equatable view wrappers.

• Input requirements include target SwiftUI source files, descriptions of observed symptoms, and optional performance trace exports (e.g., .trace files or screenshots from Instruments).

• Expected outputs are clear, ranked lists of performance culprits, step-by-step optimization recommendations, and verification procedures to ensure metrics have improved post-refactor.

• The skill encourages a structured 'Measure-Identify-Optimize-Re-measure' workflow, ensuring that every optimization is validated against baseline CPU and frame-drop data.

• Note that this skill prioritizes modern SwiftUI architectures, favoring @Observable and stable identity patterns over legacy techniques, and assumes access to standard Xcode development environments.