Mock system design interview at Meta
A live 45-minute round on one of the questions reported in Meta 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 Meta round is reported to look like
45 minutes, product-shaped: a feature of a consumer product at a scale few companies reach. Often paired with a product sense angle.
What it weighs
- Product judgement: what the feature needs to do before how it is built
- Fan-out, feeds, ranking and the hot-key problems that come with billions of users
- Practical storage and caching decisions with numbers attached
- Iterating from a simple design to one that survives the scale
The common mistake
Starting with infrastructure. The expected opening is what the user sees and what that implies, then the system that delivers it.
From public interview guides and candidate reports, not from Meta. The interviewer is an AI running in that style; it is practice, not a prediction.
Start the round
Other companies: Anthropic · Google · Amazon · OpenAI · Microsoft · Uber · Stripe · NVIDIA