{
  config,
  lib,
  pkgs,
  username,
  service_configs,
  ...
}:
{
  environment.persistence."/persistent" = {
    hideMounts = true;
    directories = [
      # System directories
      "/etc/nixos"
      "/var/log"
      "/var/lib/nixos"
      "/var/lib/systemd/coredump"
      "/etc/NetworkManager/system-connections"
      "/etc/ssh"

      # Wireguard
      "/etc/wireguard"

      # Systemd persistent timers and state
      "/var/lib/systemd/timers"
    ];

    files = [
      # SSH host keys
      "/etc/ssh/ssh_host_ed25519_key"
      "/etc/ssh/ssh_host_ed25519_key.pub"
      "/etc/ssh/ssh_host_rsa_key"
      "/etc/ssh/ssh_host_rsa_key.pub"

      # Machine ID
      "/etc/machine-id"

      # ZFS cache
      "/etc/zfs/zpool.cache"
    ];

    users.${username} = {
      directories = [
        ".ssh"
        ".config/fish"
        ".local/share/fish"
        ".cache"
        ".config/helix"
      ];

      files = [
        ".bash_history"
      ];
    };
  };

}