JavaScript
Also written as JS
The core programming language of the web, used to make pages interactive; also runs on servers via Node.js.
Think of it like
Like the electrical wiring and light switches in that house — it's what makes things actually respond when you interact with them.
Junior or senior?
Junior sounds like
Says they 'know JavaScript.'
Senior sounds like
Can walk through a tricky async bug, a performance fix, or a browser quirk they actually debugged.
Ask them
“Tell me about a tricky bug involving asynchronous JavaScript.”
Sounds like real experience
Walks through a specific async bug — a race condition, an unhandled promise rejection, a callback firing in the wrong order — and how they actually tracked it down.
Probe further if
Describes async/await or promises correctly in the abstract but can't produce a real bug they debugged, or credits the framework for handling async 'automatically.'