{
  config,
  lib,
  pkgs,
  ...
}: {
  # Boot
  boot = {
    loader.grub = {
      enable = true;
      device = "/dev/nvme0n1";
      useOSProber = true;
    };
    initrd = {
      availableKernelModules = ["xhci_pci" "ahci" "nvme" "usb_storage" "usbhid" "sd_mod"];
      kernelModules = [];
    };
    kernelModules = ["kvm-intel" "tcp_bbr" "coretemp" "nct6775"];
    kernelParams = ["threadirqs"];
    extraModulePackages = with config.boot.kernelPackages; [v4l2loopback];

    kernel.sysctl = {
      # The Magic SysRq key is a key combo that allows users connected to the
      # system console of a Linux kernel to perform some low-level commands.
      # Disable it, since we don't need it, and is a potential security concern.
      "kernel.sysrq" = 0;

      ## TCP hardening
      # Prevent bogus ICMP errors from filling up logs.
      "net.ipv4.icmp_ignore_bogus_error_responses" = 1;
      # Reverse path filtering causes the kernel to do source validation of
      # packets received from all interfaces. This can mitigate IP spoofing.
      "net.ipv4.conf.default.rp_filter" = 1;
      "net.ipv4.conf.all.rp_filter" = 1;
      # Do not accept IP source route packets
      "net.ipv4.conf.all.accept_source_route" = 1;
      "net.ipv4.conf.wlo1.accept_source_route" = 1;
      "net.ipv6.conf.all.accept_source_route" = 1;
      # Don't send ICMP redirects
      "net.ipv4.conf.all.send_redirects" = 0;
      "net.ipv4.conf.default.send_redirects" = 0;
      # Refuse ICMP redirects (MITM mitigations)
      "net.ipv4.conf.all.accept_redirects" = 0;
      "net.ipv4.conf.default.accept_redirects" = 0;
      "net.ipv4.conf.all.secure_redirects" = 0;
      "net.ipv4.conf.default.secure_redirects" = 0;
      "net.ipv6.conf.all.accept_redirects" = 0;
      "net.ipv6.conf.default.accept_redirects" = 0;
      # Protects against SYN flood attacks
      "net.ipv4.tcp_syncookies" = 1;
      # Incomplete protection again TIME-WAIT assassination
      "net.ipv4.tcp_rfc1337" = 1;

      ## TCP optimization
      # TCP Fast Open is a TCP extension that reduces network latency by packing
      # data in the sender’s initial TCP SYN. Setting 3 = enable TCP Fast Open for
      # both incoming and outgoing connections:
      "net.ipv4.tcp_fastopen" = 3;
      # Bufferbloat mitigations + slight improvement in throughput & latency
      "net.ipv4.tcp_congestion_control" = "bbr";
      "net.core.default_qdisc" = "cake";
    };
  };

  fileSystems."/" = {
    device = "/dev/disk/by-label/nixos";
    fsType = "ext4";
  };

  swapDevices = [];

  services.fstrim.enable = true;

  security = {
    protectKernelImage = true;
    sudo.extraConfig = ''Defaults timestamp_timeout=30'';
    rtkit.enable = true;
    polkit.enable = true;
  };

  # Hardware etc
  hardware = {
    cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;

    graphics.enable = true;
    graphics.enable32Bit = true;

    bluetooth.enable = true;

    pulseaudio.enable = false;
  };

  networking = {
    networkmanager = {
      enable = true;
      enableStrongSwan = true;
      packages = with pkgs; [
        networkmanager-l2tp
      ];
    };
    hostName = "nixos";
    extraHosts = ''192.168.130.211 gitlab'';
  };

  time.timeZone = "Asia/Yekaterinburg";

  i18n = {
    defaultLocale = "en_US.UTF-8";
    extraLocaleSettings = {
      LC_ADDRESS = "en_US.UTF-8";
      LC_IDENTIFICATION = "en_US.UTF-8";
      LC_MEASUREMENT = "en_US.UTF-8";
      LC_MONETARY = "en_US.UTF-8";
      LC_NAME = "en_US.UTF-8";
      LC_NUMERIC = "en_US.UTF-8";
      LC_PAPER = "en_US.UTF-8";
      LC_TELEPHONE = "en_US.UTF-8";
      LC_TIME = "en_US.UTF-8";
    };
  };
}