Environment Management

"It worked in staging" loses all meaning the moment staging is a different system than prod — different topology, different config format, a manually patched box nobody touched since it was built. Staging's entire job is to be a trustworthy predictor of what will happen in prod. Every divergence between them is a bug in that predictor, whether or not anyone notices it before the next incident.

The only differences that should exist between environments are the ones you'd defend out loud: scale, non-critical data, cost. Everything else — topology, versions, how config is structured — should be identical.

Environments should differ by the values you feed the same code, never by forking the code itself.

1. Make the difference a values file, not a branch