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In-Memory SQL Engine
Also known as: In-Memory SQL Engine (Custom)
You're implementing CREATE, INSERT, SELECT, and DELETE from scratch—no shortcuts. Interviewers love it because it exposes whether you can follow a spec precisely without drifting. The trap is getting lost in state management halfway through. Keep your table representation explicit and the rest follows.
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Low-Level Design Interview Questions
Low-level design problems test whether you can model a small API, preserve invariants, and choose storage that matches the required operations. Expect recurring shapes like rate limiters, hit counters, tic-tac-toe, file systems, and autocomplete.
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