● 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 search service queries a single Elasticsearch cluster on every keystroke for autocomplete, and tail latency is terrible. Find the bottleneck and fix it.

Sub-100ms p99 targetName the trade-off

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.