How does the Dart event loop work and what is the difference between the microtask and event queues?

Short answer

An isolate processes the microtask queue before the event queue; overusing microtasks or sustained CPU work may starve events and spoil UI responsiveness.

Explanation

Future callbacks and timers are scheduled rather than executed immediately in the same stack, but scheduling does not make CPU-bound work free. Understand the registration order and the queues before explaining a race or a frame delay.

Common mistakes

• Treating async/await as a new thread.
• Adding a long microtask loop and then being surprised that input stops.

Follow-up questions

• When do you use a Stream instead of a Future?

Sources

• Dart docs — Concurrency