Apple BackgroundTasks framework for iOS/iPadOS background processing. Use when scheduling background work, refreshing app content, running long processing tasks, implementing BGAppRefreshTask, BGProcessingTask, BGContinuedProcessingTask, or dealing with BGTaskScheduler setup, registration, submission, expiration handlers, and debugger testing commands.
Expert guidance on Swift Concurrency best practices, patterns, and implementation. Use when developers mention: (1) Swift Concurrency, async/await, actors, or tasks, (2) "use Swift Concurrency" or "modern concurrency patterns", (3) migrating to Swift 6, (4) data races or thread safety issues, (5) refactoring closures to async/await, (6) @MainActor, Sendable, or actor isolation, (7) concurrent code architecture or performance optimization, (8) concurrency-related linter warnings (SwiftLint or similar; e.g. async_without_await, Sendable/actor isolation/MainActor lint).
Build type-safe Swift state machines with enum states and action-based transitions. Use for lifecycle or protocol flows, reentrancy-sensitive operations, or async/concurrent workflows.
Type-driven domain modeling techniques for Swift using proper domain types, validation-carrying types, witness-based access control, and illegal-state elimination. Use when designing domain models, replacing primitive obsession, modeling workflows with enums/structs, adding compile-time guarantees, or discussing parse-dont-validate and making illegal states unrepresentable.
AccessorySetupKit for privacy-preserving discovery and setup of Bluetooth, Wi-Fi, or Wi-Fi Aware accessories. Use for discovery sessions, picker-based authorization, migration, accessory renaming or removal, custom filtering, and required Info.plist declarations.
Functional architecture guidance for Swift (immutability, pure functions, reducers, DI via functions).
Step-by-step guidance for maintaining a linear Git workflow using rebases, feature branches, and fast-forward merges.
Patterns and best practices for building robust AsyncStream and AsyncSequence types, learned from swift-async-algorithms.