Building a Production iOS App in 35 Hours with Claude Code

Fazm Team··3 min read

Building a Production iOS App in 35 Hours with Claude Code

Building a production app with Claude Code is a real thing now. But the experience is not what most people expect. The logic, API integrations, data models, and even the architecture come together fast. The part that eats all the time is styling.

What Goes Fast

Claude Code handles the structural work incredibly well. Setting up a SwiftUI project, defining data models, wiring up networking layers, implementing business logic - this is where AI coding shines. You describe what you want, the agent writes it, and it mostly works on the first pass.

The same applies to macOS apps. Building Fazm's SwiftUI frontend with a Rust backend, Claude Code handled the cross-language integration, the FFI bridge, and the data flow. The hard problems were not the hard problems.

SwiftUI Styling Is the Real Boss Fight

The moment you try to make things look polished, everything slows down. SwiftUI's layout system is powerful but opinionated. Getting precise spacing, custom animations, responsive layouts that work across screen sizes - this is where Claude Code starts producing output that looks "almost right" but needs constant iteration.

The feedback loop becomes: generate, preview, adjust prompt, regenerate, preview again. Each cycle is fast, but there are dozens of cycles per screen. Pixel-perfect design requires a level of visual judgment that LLMs do not have yet.

Practical Tips

A few things that help speed up the styling phase:

  • Use a design system with predefined spacing, colors, and typography tokens
  • Show Claude Code screenshots of what you want and what it produced
  • Break screens into tiny components so each iteration scope is small
  • Accept "good enough" for the first version and polish later

The 35-Hour Breakdown

Roughly 10 hours went to architecture and logic. Around 5 hours to testing and debugging. The remaining 20 hours were spent on making it look and feel production-quality. That ratio - 60% on styling - surprised everyone who tried it.

The takeaway is not that AI coding is slow. It is that the bottleneck has shifted from "can I build this" to "can I make this beautiful."

Fazm is an open source macOS AI agent. Open source on GitHub.

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