As of November 2021, all CERN websites are served by the OpenShift cloud infrastructure.
This means that everything infrastructure related is handled by the IT Drupal Infrastructure team whereas everything related to official modules or themes is handled by the Web Team. Similarly, as every website now runs on the same underlying infrastructure, we centrally manage updates to the Drupal Core and CERN-official modules and themes via the CERN Drupal Distribution*. As such, unless very specific customisation is desired, no action is necessary to ensure that your website and modules remain up-to-date. Any customised or locally installed modules remain the responsibility of the individual website owner(s), however.
The below screenshot shows my-website.web.cern.ch running in the infrastructure.
However, it is important to accentuate how CERN is not involved in the development of Drupal.
Indeed, this work is coordinated and completed by the Drupal Association (https://www.drupal.org/association/about) and the many independent developers comprising the Drupal Community. CERN thus has no say in when (or even if) updates are released, nor what is included in a given update. Instead, the CERN IT Drupal Infrastructure Team and Web Team work in close collaboration to update the CERN Drupal Distribution* following changes to Drupal.
As the Web Team is further responsible for all CERN-official modules and themes, continuous work is also being conducted to ensure compatibility with each core update. This means that website owners across CERN need not worry about updates or compatibility maintenance. However, again, any website owner with customised or otherwise locally installed modules must assume responsibility for these to ensure continued compatibility.
*additional information about the CERN Drupal Distribution is available via Gitlab.