We shipped an AI-powered iOS chat app in 8 weeks. Here is what we learned about SwiftUI, OpenAI, and app store submission. By David Friedman , Founder of AppBrewers Conversify is an AI chat app for iOS that we built to explore the intersection of mobile UX and large language models. The project took 8 weeks from concept to App Store. Here are the technical and product lessons. Tech Stack Layer Technology Why UI SwiftUI Native iOS feel, fast iteration State SwiftUI @State + Combine Built-in reactivity AI OpenAI GPT-4o Best reasoning quality Backend Firebase Cloud Functions Serverless, scalable Auth Firebase Auth Apple Sign-In support Storage Firebase Firestore Real-time sync Analytics Mixpanel User behavior insights Key Technical Decisions 1. Streaming Responses Users expect instant feedback. We implemented server-sent events for token-by-token streaming. Challenge: SwiftUI lists re-rendering on every token caused UI jank. Fix: Batched tokens in 50ms windows and used diffable data sources. 2.…