FrontendHigh signal
Web Workers
Also written as Web Worker
A way to run heavy JavaScript in the background of a web page, so expensive work (parsing big files, image processing) doesn't freeze the screen.
Think of it like
Sending a colleague to the back office to crunch numbers, so the person at the front desk can keep serving customers.
Junior or senior?
Uncommon, and a real performance signal when genuine. Usually appears in data-heavy apps, editors, or in-browser tools.
Ask them
“What was freezing the page, and how much did moving it to a worker help?”