Git is the way. I run a Gitea instance so all my code lives on my home server but have used Github in the past.

Like others have said, Immich is great for this. It's damn near a copy of Google Photos without all the Google which is very nice. Fair warning however, I'm about to enter week two of backing up. I've got 14000+ assets to upload, and from what I've seen the first upload is the most brutal. Good luck, traveler!

Depending on how you're going about having these media files, you might want to take a look at the *arr stack