Frequently asked questions

A practice platform for the data modeling interview round — the highest-elimination, least-practicable part of data engineering interviews. You design schemas on an interactive canvas, get instant deterministic feedback, and run timed mock interviews with an AI interviewer.

Data engineers, analytics engineers, and people breaking into the field who have an interview coming up and want a real venue to practice design judgment — not just SQL syntax.

LeetCode-style and SQL sites drill query syntax. SchemaLab drills design judgment: grain, keys, slowly changing dimensions, conformance, and fact-type choices, verified against the model you draw. SQL practice is a different game already owned by other tools.

Structural and modeling checks (Layers 1 and 2) are deterministic pure functions — consistent and explainable, with no AI in the loop. They are the authoritative pass/fail signal. AI (Layer 3) then provides a design review constrained by those deterministic facts, so it judges rather than re-deriving the answer.

AI feedback is assistive and can be imperfect, which is exactly why it is bounded by the deterministic checks: the checks decide correctness; the AI explains trade-offs and coaches. It will not contradict a design that passes the deterministic rules.

No. Company-themed tracks labeled “<company>-style” are reconstructions of publicly documented interview formats, for practice realism. They are not official questions and are not affiliated with any named company.

There is a free tier for trying the practice loop, with paid plans for unlimited deterministic checks, the in-workspace tutor, and full mock interviews. You can cancel a subscription at any time; access continues until the end of the billing period.

We collect the minimum needed to run the product and never sell your data. You can delete your account and content at any time. See the Privacy Policy for processors (Supabase, Stripe, PostHog, Anthropic) and retention details.

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