These are brief tips that I make for myself for some of the things I easily forget.

• FRP Setup GuideExpose a home server past CGNAT with FRP + a VPS, secured with TLS certs and token auth.
• VPS Setup GuideWireGuard VPN on a VPS to port-forward a home service past ISP CGNAT, with NAT and firewall rules.
• Crontab ReferenceCron field format, @reboot/@daily shortcuts, and the PATH & output gotchas that bite you.
• Systemd Service ReferenceAnatomy of a unit file plus the daemon-reload, enable --now, and journalctl commands.
• UFW ReferenceEnable/inspect UFW, set default policies, rate-limit SSH, and manage rule ordering.