Mock system design interview at OpenAI
A live 45-minute round on one of the questions reported in OpenAI interviews, run by an AI interviewer that asks one thing at a time, probes what you say, and weighs what that round is reported to weigh. It ends with a debrief: a score, what was strong, what was missing.
Design Slack
Real-time team messaging: channels, DMs, presence, history and search for millions of concurrent users.
You will not see the requirements, the numbers or the diagram before you start — that is the point.
What the OpenAI round is reported to look like
45–60 minutes, frequently on the infrastructure behind model serving, data pipelines or developer-facing APIs.
What it weighs
- Latency and cost tradeoffs under expensive, constrained compute
- Streaming, batching and backpressure on the request path
- Safety, abuse and quota mechanics as part of the design, not an afterthought
- Pragmatism: what you would actually ship first
The common mistake
Treating an AI product as a standard CRUD app. The interesting constraints are capacity, streaming and cost per request.
From public interview guides and candidate reports, not from OpenAI. The interviewer is an AI running in that style; it is practice, not a prediction.
Start the round
Other companies: Anthropic · Google · Meta · Amazon · Microsoft · Uber · Stripe · NVIDIA