I built an iOS app in just two days thanks to AI - and it was exhilarating

The article recounts a developer’s experience using Xcode 26.3’s enhanced agentic AI to migrate and expand an app into a sewing pattern manager in under two days, adding ML features like envelope scanning, OCR, barcode filtering, and NFC-based tracking. It highlights major improvements over Xcode 26.1, while noting serious pain points with runaway background agents and token consumption, ultimately mitigated by a strict workflow rule (no background agents, frequent status updates) that restored speed and reliability.