@kaia For Immich I'm using pretty much the exact Compose file recommended on their guide, with only minor changes to the volumes and labels for networking. https://immich.app/docs/install/docker-compose/
For Syncthing, this is it: https://pastebin.com/Rn6K1U14
I'm not mapping ports in the Compose file because I have it routed through the reverse proxy with TCP/UDP streams.
Also, that last label is something I'm still working on, not ready for release yet, but it basically automates the network conn. to the reverse proxy.