In-Memory KV Cache with WAL Log

Durable In-Memory Key-Value Cache Backed by a WAL System Design — Onsite / Phone — Software Engineer Problem Statement Create a high-speed in-memory key-value cache offering GET, PUT, and DELETE. Unlike an ordinary best-effort cache, it must make acknowledged writes durable through a Write-Ahead Log (WAL). It needs fast crash recovery, TTL expiration, protection against hot-key pressure, and horizontal expansion across multiple hosts. Picture it as a tier between an…