● Free · no signup · ~5 min
Try a system design drill
One focused, interview-style prompt. Write a short answer and an AI interviewer grades it in seconds.
The prompt
A notification worker pulls jobs from one queue with a single consumer, and the backlog grows during spikes. Identify the bottleneck and fix it.
Spiky loadOrdering matters for some events
Your answerFill in each line — schema, bullets, or prose.
Bottleneck ◯·Fix ◯·Trade-off ◯
No diagram needed for a drill — that's what the full interview is for.