requestAnimationFrame vs timeout

A production symptom appears first: flaky tests, stale state, slow UI, late cleanup, or growing memory. This improves smoothness in drag interactions, charts, canvas work, scroll effects, and layout measurement.

Using setTimeout for visual animation timing.

Fix the root scheduling, cleanup, or concurrency pattern instead of adding arbitrary waits.

try {
  await operation();
} finally {
  cleanup();
}

The console lane proves the visible order: sync -> paint work -> timer work. The active line and queues show why source order changed.

Reproduce the symptom with a small test, apply the safer pattern, then verify the flaky, slow, or leaking behavior disappears.