Chezmoi was a complete workflow changer for me.
https://www.chezmoi.io/
Let's me manage/synchronize my configs between systems. It has built in variables and scripting support so you can ignore sections of files or specific sections of files on certain systems, write specific configs for specific systems based on hostname or OS.
It's a bit of work to get an understanding of, but incredibly powerful once you do.
Whenever I setup a new system now, I install chezmoi, clone my comfig repo and then initialize it and it uses the chezmoi scripts to automatically installs all my programs and copies in the needed config files.