Mobile Lens Profiler: Case Study
Article Summary
Snap's engineering team just dropped a masterclass in mobile performance debugging. Ever wonder why your AR lens stutters on the first frame?
Snap published a detailed case study walking through real-world profiling of a Snapchat Lens built with their Lens Studio 5.1. They used Google's Perfetto UI to trace performance on an iPhone 13, examining everything from lens activation to frame drops.
Key Takeaways
- Lens activation took 173ms, with 125ms spent on main rendering thread
- First frame slowdown traced to deferred GPU texture uploading for jacket and hair assets
- Achieved 30 FPS after initial load, down from 28 FPS with first frame included
- ShapeTrack face detection retries drain battery via expensive neural network calls
- Shader caching prevented major slowdowns during lens loading phase
Critical Insight
The case study demonstrates how to pinpoint GPU driver stutters and texture upload bottlenecks that cause frame drops in AR experiences.
