A backend loop is four to six stages: a recruiter screen, a 45 to 60 minute technical phone screen in a shared editor, a coding round, the 60 minute system design round that carries most of the signal, a behavioural and ownership round, then a hiring manager or bar raiser. GhostPilot runs in the browser side panel for all of them.
Free tier: 10 minutes of live interview time a week, no card. Windows desktop app for full-screen share.
Sixty minutes, and the interviewer is marking breadth as much as depth. Question detection catches the prompt, and a structured answer arrives about two seconds after it ends: token bucket against sliding window counter, where the counter actually lives, what happens to your limits during a Redis failover, and what you return on a rejection. You still draw the thing and defend the tradeoff. What it buys you is not blanking on the fourth algorithm at minute forty.
Parse a log stream, implement an LRU cache, write a small API handler with the edge cases handled. Coding mode captures the on-screen problem with one shortcut and returns a worked solution. The more useful half is quieter: live transcription keeps the constraints the interviewer adds mid-round on screen, so "now make it thread-safe" is still in front of you when you are three levels deep in the code and have stopped listening properly.
"A query that used to take 50ms now takes 5 seconds." "How would you run a zero-downtime migration on a live table?" "Tell me about a production incident you were involved in." The first two want an ordered method: query plan, index selectivity, N+1, then expand-and-contract with a backfill and a dual-write window. The third is a story, and behavioural questions are handled differently from technical ones, so it comes back with a root cause and what changed afterwards rather than a list of flags.
Worth saying plainly: a design round rewards defending a decision under pressure, and nothing on screen does that part for you. This is for recall under a clock.
The accurate version, because a wrong answer here costs you the interview. The Chrome extension lives in the browser side panel: it is not captured when you share a single tab, nor when you share a window with the panel popped out. Like every extension, it is visible if you share your entire screen. The Windows desktop app is different. It excludes its own window at the operating-system level, so it stays out of screen shares, recordings and screenshots, and sits in the taskbar as "GP Helper".
Backend loops often run in a shared editor tab, and a tab share does not capture the side panel. If your interviews force a full-screen share, the desktop app is the right tool, and the only one we would stand behind.
Run it against a phone screen first
Ten minutes of live interview time a week, free, no card. Enough to see how it behaves on a mock system design prompt before you point it at a loop you care about.
Install on Chrome