I manage my dotfiles with Nix and Homemanager on the atomic and immutable distribution Fedora Kinoite. I use nix packages to avoid flatpak and layering to the base image. Nixpkgs is one of the largest linux package bases, for what is not available I use podman containers. Home-manager control absolutely everything declaratively and even deployment with rpm-ostree.

Preparation

sudo tee /etc/ostree/prepare-root.conf <<'EOL'
[composefs]
enabled = yes
[root]
transient = true
EOL

rpm-ostree initramfs-etc --reboot --track=/etc/ostree/prepare-root.conf

Install Nix

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | \
    sh -s -- install ostree --no-confirm --persistence=/var/lib/nix

Add Nix Unstable

nix-channel --add https://nixos.org/channels/nixpkgs-unstable nixpkgs
nix-channel --update

Install Home-Manager

nix-channel --add https://github.com/nix-community/home-manager/archive/master.tar.gz home-manager
nix-channel --update

nix-shell '<home-manager>' -A install

Rebuild the configuration

git clone https://github.com/DXC-0/Nix-Dotfiles.git
cd Nix-Dotfiles
mkdir -p $HOME/.config/home-manager
mv * $HOME/.config/home-manager

home-manager switch