Chaos Engineering for Node.js Without the Infrastructure

Chaos engineering sounds expensive. Netflix built Chaos Monkey to randomly kill production servers. Google runs DiRT (Disaster Recovery Testing) across their entire infrastructure. Amazon does game days where they intentionally take down services. You're building a Node.js API. You don't have a platform team. You don't have a chaos infrastructure. But you still need to know: what happens when your dependencies get slow? The good news is that 80% of the value of chaos engineering comes from one question, and you can answer it locally in five minutes. The one question that matters What does my application do when a dependency responds slowly or not at all? Not "what if the server catches fire" — that's infrastructure chaos. What about application chaos: the database is slow, the payment API is timing out, Redis is having a bad day. These happen constantly in production and they're almost never tested. The failure modes look like this: Your DB gets slow under load → your API response times climb → your timeout fires → you retry → now you're sending twice the load to an already-slow DB Your Redis cache goes down → every request hits Postgres directly → Postgres gets slow → same cascade Stripe's API takes 3 seconds instead of 200ms → your checkout route times out → users get errors → you're losing revenue Every one of these is a latency failure , not a crash. The service is still up. It's just slow. And slow is the hardest failure mode to test because your local environment is fast. Why local testing misses this When you test locally, your "database" is either: A real local Postgres running on the same machine (sub-millisecond latency, not production-like) A mock that returns instantly ( jest.fn().mockResolvedValue(data) ) A fake with a flat delay ( await sleep(200) ) None of these produce realistic latency. A real production database has: Fast responses most of the time (p50 ~5ms) Occasional slowdowns (p95 ~50ms) Rare but real spikes (p99 ~200ms, p99.9 ~2000ms) The spik