One open-ended scenario, one long conversation about tradeoffs.
One extended conversation around a single scenario, not a series of short questions — expect to go deep on 2-3 areas the interviewer picks based on what you say, rather than covering many topics shallowly. This runs longer than the question-based tracks.
Design the backend for a chat application like WhatsApp.
Design a news feed system like Twitter's home timeline.
These are a few examples — the real scenario for your session is chosen at random from a larger pool, matched to your chosen difficulty.
Frequently asked questions
Is System Design five separate questions like the other tracks?
No — System Design practice is one extended conversation around a single scenario, going deep on 2-3 areas rather than covering many questions shallowly. Expect this to run longer than the question-based tracks.
Can I choose the difficulty?
Yes — easy, medium, or hard, chosen right before you start. It changes how aggressively the interviewer probes and how strictly it scores your reasoning.
Is it free?
Yes — every account gets 5 interviews a month, any track, for free. Pro upgrades to unlimited interviews for $99/month.
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5 free interviews every month, any track, no card required.