How to profile jank in a Flutter app with DevTools
Step-by-step guide to finding and fixing jank in Flutter 3.27 with DevTools: profile mode, the Performance overlay, the Frame Analysis tab, the CPU Profiler, raster vs UI thread, shader warm-up, and Impeller-specific gotchas. Tested on Flutter 3.27.1, Dart 3.11, DevTools 2.40.