Earlier this week Alex and Dave gave a talk at DrupalCon North America 2021. The talk took audience members on a journey of how they could improve the security of their Drupal sites by achieving an "A+" score on the Mozilla Observatory tool, from a starting point of a newly installed Drupal 9 "Umami" demonstration site.
The demonstration site that was created as part of this session can be found online at drupalsecurity.co.uk for your evaluation.
The presentation slides can be downloaded as a PDF.