The video is rather long so I tried to come up with a approximate "table of contents".

[Of course if you suffer FOMO, like I do : go ahead and watch the whole thing ;-)]

0:00 introduction
3:15 zsh
8:00 dotfiles can live in a git repo (spoiler : uses symlinks)
8:30 more about customizing zsh (aliases, env vars, oh my zsh, plugins, themes)
11:58 homebrew
12:55 mas ("mac app store") -- MacOS specific.
13:45 Brewfile for reinstalling the system (goes over the list of apps)
17:10 mackup, to save your dotfiles
19:25 system settings : another script to recover them (has to be maintained)
21:00 Dries goes through his own documentation at https://github.com/driesvints/dotfiles
26:00 Good bye

HTH

Everything You Need to Know About Dotfiles