How GitHub reduced testing time for iOS apps with new runner features
Article Summary
GitHub's iOS team just cut their CI testing time by 60%. Here's how they did it with Apple Silicon runners and some smart architectural changes.
The GitHub iOS team partnered with GitHub Actions to overhaul their testing pipeline. They moved from a monolithic 38-minute build process to a parallelized approach using M1 macOS runners, fundamentally changing how they ship features like Copilot Chat and code search to mobile users.
Key Takeaways
- Split monolithic test suite into 60 independent module jobs running in parallel
- Smallest modules now complete in 2-3 minutes on M1 runners
- Total CI time dropped from 38 minutes to 15 minutes (60% reduction)
- Native ARM architecture matches developer laptops, eliminating cross-compilation issues
- Enterprise accounts get 50 concurrent runners for massive parallelization
Critical Insight
By breaking down their monolithic build and leveraging Apple Silicon runners, GitHub reduced iOS testing time from 38 to 15 minutes while improving developer feedback loops.
