

Server or desktop, and what types of files? I find that a self-hosted version of NextCloud does pretty well for keeping contacts, images, and videos in sync.
(You could run it on a Pi as an intermediary to both if desired)
I used to use stuff like AndFTP in the past for similar functions
Or how bumblebee did an “rm -rf” on uninstall without a quoted path, which ended up nuking important directories