A Drupal 11 cutover for a professional regulator

A regulator's website is part of a statutory process. Licence applications, complaints and renewals run through it, which makes an upgrade a risk-management exercise as much as a technical one.

So it was run as one: a readiness assessment first, a contrib compatibility matrix, a technical appendix with the effort behind each line, weekly build logs, and a cutover runbook with an emergency-freeze procedure attached. The interesting engineering was in the long tail of webform-driven processes and the group-scoped editorial permissions, both of which had to behave identically the morning after.