Frontend System Design
/Expert
Event Loop
Definition
The Event Loop is the mechanism that allows Node.js and browsers to perform non-blocking I/O operations despite JavaScript being single-threaded. It constantly monitors the Call Stack and the Task Queues, pushing tasks to the stack when it is empty.
Explain Like I'm New
The Event Loop is a bouncer at a club. He constantly checks if the dance floor (Call Stack) is empty. If it is, he lets the next person from the VIP line (Microtasks) in. If the VIP line is empty, he lets one person from the regular line (Macrotasks) in.
Architecture & Flow
Interview Questions
basic
- Can you explain the basic concept of Event Loop?
- Why is Event Loop important in frontend system design?
intermediate
- How does Event Loop impact perceived performance and user experience?
- Describe a scenario where you had to debug an issue related to Event Loop.
advanced
- In a highly scaled enterprise system, how do you optimize Event Loop?
- What are the security implications of Event Loop?
trick
- Can Event Loop be entirely bypassed or disabled? What happens if it is?