2026-05 - W4

Being oncall taught me everything - Yao Yue

Without exageration, being oncall made me the engineer I am. … It taught me that being fast most of the time is not as important as being predictable, and that tail latencies are often far more important than median or mean in a system of scale. It taught me the value of simple and clear architecture in moments of crisis, the tradeoffs of common design patterns that textbooks never told you about, the interaction between an application and its environment, and the deeply connected nature of services in a datacenter. It taught me that operational excellence—thorough observability, consistent configuration, automation readiness, sensible default values—comes from good design decisions instead of last-minute patching two weeks before launch. My taste as a software engineer is that of a highly skeptical operator, and it has remained so long after I stopped being oncall.