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.…