Redis Is Not a Database (Until You Treat It Like One)

Redis is one of those tools almost every backend engineer has used—and many have misused. It starts simple: “Let’s just cache it.” Then Redis works so well that it slowly becomes the system . Before you know it, business logic depends on Redis keys, not your primary database. That’s where things usually go wrong. Redis is not a database by default. But with the right discipline, configuration, and mindset—it can behave like one. This article is about drawing that line clearly, from real production experience. Why Redis Is Not a Database (By Default) Redis was designed for speed first , durability second. Out of the box, Redis optimizes for: In-memory access Low latency Simple data structures Fast eviction and expiration What it does not guarantee by default: Strong durability Crash-safe persistence Complex querying Schema enforcement Long-term data retention If you treat Redis like PostgreSQL without adjusting anything, you’re setting yourself up for silent data loss. The Common Trap: