CharlesWiltgen

Use when writing ANY async code, actors, threads, or seeing ANY concurrency error.

Use when the user mentions concurrency checking, Swift 6 compliance, data race prevention, or async code review.

Use when profiling async/await performance, diagnosing actor contention, or investigating thread pool exhaustion.

Use when the user mentions Core Data review, schema migration, production crashes, or data safety checking.

Use when debugging schema migration crashes, concurrency thread-confinement errors, N+1 query performance, SwiftData to Core Data…

Use for Core Location troubleshooting - no location updates, background location broken, authorization denied, geofence not triggering

Use for Core Location implementation patterns - authorization strategy, monitoring strategy, accuracy selection, background location

Use for Core Location API reference - CLLocationUpdate, CLMonitor, CLServiceSession, authorization, background location, geofencing

Use when indexing app content for Spotlight search, using NSUserActivity for prediction/handoff, or choosing between CSSearchableItem and…

Use when the user has a crash log (.ips, MetricKit JSON, legacy .crash text, .xccrashpoint bundle, or pasted text) that needs analysis.

Use when working with ANY data persistence, database, storage, CloudKit, migration, or serialization.

Use when the user mentions database schema review, migration safety, GRDB migration audit, or SQLite schema checking.