Staging is never hammered with production traffic, often not exposing problems. It's a sanity check for developers and QA, essentially. On the scale of Google,

Staging is never hammered with production traffic, often not exposing problems. It's a sanity check for developers and QA, essentially. On the scale of Google, you test in production, but with careful staged canary deployments. Even a 1% rollout is more than most of us have ever dealt with.