Frontend System Design
/Expert
Microtasks
Definition
The Microtask Queue contains callbacks from Promises (`.then/catch/finally`) and `queueMicrotask()`. It has the highest priority. The event loop will completely drain the entire Microtask Queue before moving to Macrotasks or rendering.
Explain Like I'm New
Microtasks are emergencies. If a doctor (Event Loop) finishes seeing a patient, they will check for emergencies (Microtasks) and treat ALL of them before calling the next regular patient in the waiting room.
Interactive Example
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Interview Questions
basic
- Can you explain the basic concept of Microtask Queue?
- Why is Microtask Queue important in frontend system design?
intermediate
- How does Microtask Queue impact perceived performance and user experience?
- Describe a scenario where you had to debug an issue related to Microtask Queue.
advanced
- In a highly scaled enterprise system, how do you optimize Microtask Queue?
- What are the security implications of Microtask Queue?
trick
- Can Microtask Queue be entirely bypassed or disabled? What happens if it is?