A table view stutters while scrolling — what do you do?
Measure first
Don't guess, profile: Instruments → Animation Hitches (shows which frame stage dropped: commit, render, main thread) and Time Profiler (what exactly occupies the main thread). In Xcode — Debug View Hierarchy and the colour overlays "Color Blended Layers" / "Color Offscreen-Rendered". At 120 Hz a frame has only 8 ms.
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