reliability
2 articles
-
"It shows me old data" — how to test caches, the quietest source of bugs
The "user sees stale data" bug doesn't reproduce, gets closed as "went away on its own" — and comes back a week later. That's not mysticism, that's a cache. A first-person take: the map of six caching layers (browser, CDN, gateway, application, database, mobile client), invalidation as the main test case, caches leaking other users' data, cache stampede after a deploy, the "every case twice — cold and warm" rule, and why testing with the cache off means testing a system that doesn't exist.
-
Chaos Engineering for QA: deliberately breaking the system to test resilience
Resilience you never tested with a deliberate failure is an assumption, not a fact. Chaos Engineering for QA: the steady-state hypothesis, blast radius and the abort button, what failures to inject (instance kill, latency, dependency outage, resource exhaustion, zone outage), tools (Chaos Monkey, Gremlin, Chaos Mesh, AWS FIS, Toxiproxy), Game Days, the QA role (graceful degradation, retries, circuit breakers, observability) and a safe-experiment checklist.