My personal sauce is Emacs with org-mode configs to be tangled, far more efficient than anything else tried before to manage dotfiles I care, ignoring those I do not care...

NixOS (since unfortunately Guix System is still a bit raw for me) complete tha game allowing to easy tangle the whole system config and generate a custom iso with Emacs and all the rest.

Zsh complete the game as shell, eshell honestly it's on my list but I still can't use it daily...