As asked
A newly shipped animated navigation pattern feels smooth in the prototype but janky in production on mid-range Android devices. How do you diagnose and fix it?
Sample answer outline
Start by reproducing on target hardware, not a high-end design machine. Look for layout thrashing, expensive shadows or blurs, main-thread JavaScript work, large images, and animations of layout properties instead of transform or opacity. The candidate should know how to work with engineering using browser performance tools, Android profiler, or React Native performance monitors. Good fixes include simplifying the motion, moving work to the compositor or native driver, reducing overdraw, and setting a clear frame budget. Interviewers are listening for a designer who can preserve intent while cutting implementation cost.
Expect these follow-ups
- Which visual effects are most likely to cause overdraw?
- How do you decide whether to simplify the design or ask engineering for optimisation?
- What performance acceptance criteria would you set before launch?