I Bought the Cheapest Redis and Dared It to Fail: The Circuit Breaker That Made Cache Optional (Series Part 11)

I noticed it as a silence first. A request that normally felt instant took long enough that I caught myself staring at the logs like they owed me money. Nothing was “down.” No exception. No crash. Just… slow. And the slow wasn’t mysterious: Redis had stopped answering. This is Part 11 of my series “How to Architect an Enterprise AI System (And Why the Engineer Still Matters)” . Part 10 was about privacy as a runtime toggle; this one is about a different kind of toggle: making Redis optional —not by hand-waving, but by design. The uncomfortable truth is that a cache is only “an optimization” if your system behaves that way when it disappears. Most systems don’t. They say cache is optional, then they couple correctness to it with a thousand tiny assumptions until the first hiccup turns into an outage. My core decision was simple to state and annoying to execute: I chose the cheapest Redis tier, and I wrote a circuit breaker so the app survives without Redis. That single decision forced m