Versioned Key-Value Store with Point-in-Time Reads
Asked at Citadel · Coding Questions · Difficulty: Medium · Last asked Feb 18, 2026
Build a small key-value store that remembers every value a key has ever had, each stamped with the time it was written. A reader can then ask what a key looked like at any moment in the past, for example to reproduce a report exactly as it was at a given time.
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