Docker image layering and nightlies for the heavier installs has worked pretty well for me. Dependencies from things like npm, composer etc are all build time still but more of the base stuff is on a weekly build cycle. We just do notifications if the nightlies fail to manually resolve it which is very very seldom
So for me personally, Jellyfin isn’t worth actually paying to back up all 16+TB, but my Nextcloud absolutely is. I do Restic for the data I want with a pretty long retention and have had great luck with restoring off of it