3 Techniques We Used to Improve Skyscanner for iOS Performance

Skyscanner's iOS team discovered their app was lagging on nearly half their user base. The culprit? Testing only on high-end devices.

The Skyscanner engineering team shares how they systematically improved iOS app performance using measurement-driven optimization. Their approach focused on identifying bottlenecks that affected users on older devices like the iPhone 5, which represented 10% of their user base.

Key Takeaways

• Removed unnecessary accessibility label calculations for 8.9% performance boost
• Implemented date cache to eliminate redundant calculations, gaining 3.2% improvement
• Used Instruments profiler to identify main thread bottlenecks causing UI lag
• Built custom FPS monitoring tool to track real-world performance during testing
• Improved smooth navigation from 61% to 97.47% of users maintaining 30+ FPS

The team's custom FPS monitoring tool revealed performance patterns that standard profiling missed, fundamentally changing how they approach optimization.