March 1, 2022
Convert an Empty Upstream Drupal Site to a Composer Managed Site - Convert an empty upstream Drupal 9 site to use Composer to manage deployments and dependencies. You can then switch from empty to the new Integrated Composer drupal-recommended upstream while remaining on Drupal 9. To convert, ensure your site has the Pantheon empty repository in its upstream. For more information, refer to our documentation.
Managing Drush Versions on Pantheon - Pantheon currently supports Drush versions 8, 10, and 11. For sites that are managed by Composer, a site-local installation of Drush is recommended. To learn about Pantheon's default Drush version, compatibility, requirements, and how to implement site-local usage, refer to our documentation.