Things that bit me when staging and prod "shared just one small thing."

Draft — coming soon.

A field guide to the environment-isolation failures that show up six months into a Terraform rollout — after the happy path is deployed, after the team has moved on to new features, and somebody in staging runs terraform destroy with the wrong AWS_PROFILE.

Topics covered:

• Shared secrets that weren’t supposed to be shared (and how the “just this one API key” pattern metastasizes)
• External DNS provider drift: when your zone file stops matching your Terraform state and neither side notices
• Console-vs-state divergence — the quiet drift from engineers clicking “just this once” in the AWS console
• The boring account-boundary practices that actually prevent this

Anonymized. Based on patterns observed across multiple engagements.