Building a batch image converter in SwiftUI hit me with a thread-safety problem. Tap "Convert" on 100 photos. Each runs on a background queue. All might touch shared state — progress, cancellation flags, and result cache. Old fix: locks, GCD queues, a fragile model. Swift actors made it ~1 line.

Shipped my first iOS app — Image Converter Plus. Batch JPEG/PDF/PNG/WebP/HEIC/AVIF/TIFF converter for iPhone, 60+ languages, built solo in SwiftUI. 5 months of nights and weekends. Going to share the post-launch reality here for 3 weeks. apps.apple.com/us/app/image...