I use primarily linux but these are the tools i use:

Ansible - I can bootstrap a new linux install with all of my configs in ~10min, this has saved me countless hours of time. My linux installs are heavily modified (tiling window manager, lots of custom hotkeys, custom ricing)

Git - I sync all of my dotfiles to git and and can keep them in sync between PCs.

Syncthing - My dev folder and a few other important folders are kept in sync between all of my PCs using syncthing. I can save a file on my desktop and turn to my laptop and the file will almost instantly be there.