Building the Same App in SwiftUI, Kotlin Multiplatform, and Flutter — What 281 vs. 75 Lines of Code Teaches Us
Article Summary
Dr. Simon Bogutzky built the same bill-splitting app three times. The line count difference? 75 vs. 281.
This isn't another framework comparison with benchmarks and feature lists. It's a hands-on experiment implementing identical functionality in SwiftUI, Kotlin Multiplatform with Compose, and Flutter to reveal what those code differences actually mean for your team.
Key Takeaways
- SwiftUI needs one-third the code of Flutter, one-quarter of KMP/Compose
- KMP's extra 200 lines buy proper architecture and platform abstraction
- SwiftUI handles state and navigation automatically; others require explicit setup
- Flutter's hot reload wins developer experience, but manual cleanup risks leaks
- All three perform well at small scale; differences emerge in complex apps
Critical Insight
SwiftUI wins on elegance for iOS-only apps, KMP/Compose invests in scalable architecture for cross-platform, and Flutter balances pragmatic speed with mature tooling.
