WebSockets — Part 4: Senior-Level Interview Q&A

What is this?

This is your mock-interview session. For each question we'll do three things: decode what the interviewer is really asking, walk through a strong answer built on Parts 1–3, and call out the senior line — the one sentence that signals you've actually run these systems, not just read about them.

The big secret: at Staff/Principal level, nobody's grading you on "what is a WebSocket." They're listening for judgment — do you reach for the simplest tool, do you know the failure modes, do you name the trade-off out loud? Every answer below is built to show that.