Implement a Recoverable In-Memory Key-Value Store
Company: OpenAI
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Technical Screen
Overview: Build a single-process in-memory key-value store that can recover from its local append-only history after a crash. Define its durability contract and address torn writes, corruption, concurrent callers, startup cost, compaction, arbitrary byte values, and failure testing.