Blue-Green Data

Concepts: paEnvironmentMgmt

What They Want to Hear 'Blue (current prod) and green (new version) run in parallel on the same input data. Both write to separate output locations. Compare outputs. If they match, switch consumers from blue to green by updating a view or alias. If they differ, investigate before switching. Rollback = switch the view back to blue. Zero downtime because consumers always read from the view, and the view always points to valid data.'