Glossary
Environment Isolation
Environment isolation means development, staging, and production environments don't share credentials, don't share data, and aren't reachable from each other by the same access that's valid within just one. Without that separation, a mistake made in a lower-stakes environment — a leaked test credential, an overly permissive debug endpoint — can become a path into the production environment it was never meant to touch.
A frequent, quiet violation is production data copied into a lower environment for testing convenience, without the same access controls following it there. The data has moved somewhere less protected while remaining just as sensitive as it was in production, which defeats the isolation the environments were supposed to provide in the first place.