Development

Use when debugging schema migration crashes, concurrency thread-confinement errors, N+1 query performance, SwiftData to Core Data bridging, or testing migrations without data loss - systematic Core Data diagnostics with safety-first migration patterns

Use when building, fixing, or improving ANY iOS UI including SwiftUI, UIKit, layout, navigation, animations, design guidelines. Covers view updates, layout bugs, navigation issues, performance, architecture, Apple design compliance.

PHPicker, PhotosPicker, photo selection, limited library access, presentLimitedLibraryPicker, save to camera roll, PHPhotoLibrary, PHAssetCreationRequest, Transferable, PhotosPickerItem, photo permissions

Use when app runs at unexpected frame rate, stuck at 60fps on ProMotion, frame pacing issues, or configuring render loops. Covers MTKView, CADisplayLink, CAMetalDisplayLink, frame pacing, hitches, system caps.

Apple platform typography reference (San Francisco fonts, text styles, Dynamic Type, tracking, leading, internationalization) through iOS 26

Use when integrating ANY iOS system feature - Siri, Shortcuts, Apple Intelligence, widgets, IAP, camera, photo library, photos picker, audio, haptics, localization, privacy. Covers App Intents, WidgetKit, StoreKit, AVFoundation, PHPicker, PhotosPicker, Core Haptics, App Shortcuts, Spotlight.

Use when indexing app content for Spotlight search, using NSUserActivity for prediction/handoff, or choosing between CSSearchableItem and IndexedEntity - covers Core Spotlight framework and NSUserActivity integration for iOS 9+

Use when build times are slow, investigating build performance, analyzing Build Timeline, identifying type checking bottlenecks, enabling compilation caching, or optimizing incremental builds - comprehensive build optimization workflows including Xcode 26 compilation caching

Use when making design decisions, reviewing UI for HIG compliance, choosing colors/backgrounds/typography, or defending design choices - quick decision frameworks and checklists for Apple Human Interface Guidelines

Use when SwiftData migrations crash, fail to preserve relationships, lose data, or work in simulator but fail on device - systematic diagnostics for schema version mismatches, relationship errors, and migration testing gaps

Use when testing async code with Swift Testing. Covers confirmation for callbacks, @MainActor tests, async/await patterns, timeout control, XCTest migration, parallel test execution.

Use when needing thread-safe primitives for performance-critical code. Covers Mutex (iOS 18+), OSAllocatedUnfairLock (iOS 16+), Atomic types, when to use locks vs actors, deadlock prevention with Swift Concurrency.

Use when implementing iOS 26 SwiftUI features - covers Liquid Glass design system, performance improvements, @Animatable macro, 3D spatial layout, scene bridging, WebView/WebPage, AttributedString rich text editing, drag and drop enhancements, and visionOS integration for iOS 26+

Reference — SwiftUI stacks, grids, outlines, and scroll enhancements through iOS 26

Use when you see 'actor-isolated', 'Sendable', 'data race', '@MainActor' errors, or when asking 'why is this not thread safe', 'how do I use async/await', 'what is @MainActor for', 'my app is crashing with concurrency errors', 'how do I fix data races' - Swift 6 strict concurrency patterns with actor isolation and async/await

Use when optimizing Swift code performance, reducing memory usage, improving runtime efficiency, dealing with COW, ARC overhead, generics specialization, or collection optimization

Use when localizing apps, using String Catalogs, generating type-safe symbols (Xcode 26+), handling plurals, RTL layouts, locale-aware formatting, or migrating from .strings files - comprehensive i18n patterns for Xcode 15-26

Use when making app surface in Spotlight search, Siri suggestions, or system experiences - covers the 6-step strategy combining App Intents, App Shortcuts, Core Spotlight, and NSUserActivity to feed the system metadata for iOS 16+

Reference — Comprehensive SwiftUI navigation guide covering NavigationStack (iOS 16+), NavigationSplitView (iOS 16+), NavigationPath, deep linking, state restoration, Tab+Navigation integration (iOS 18+), Liquid Glass navigation (iOS 26+), and coordinator patterns

Use when Now Playing metadata doesn't appear on Lock Screen/Control Center, remote commands (play/pause/skip) don't respond, artwork is missing/wrong/flickering, or playback state is out of sync - provides systematic diagnosis, correct patterns, and professional push-back for audio/video apps on iOS 18+