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Time Based Key-Value Store
Each key holds multiple values at different timestamps, and you need the most recent value at or before a given time. Interviewers love it because it reveals your binary search precision—one wrong boundary update can loop forever. The trap is boundary drift. Nail this and temporal queries become second nature.
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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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