When I arrived, this site was on Drupal 7 and had not had a security update in five years. The site used an install profile that was no longer supported. After a series of incremental updates I removed the install profile and got the site running current Drupal 7. Phase 2 involved upgrading the site to Backdrop CMS.
The site holds roughly forty years of the Model Aviation magazine. Every page is a scanned image. As a result of this project I ported the S3 File System module from Drupal 7 to Backdrop CMS. This lowered the storage requirements for hosting the site because the images were in an S3 bucket separate from the site files.