nginx 
Protecting My Server with Fail2ban
How I set up Fail2ban on my server to stop brute force attacks, SSH hammering and Nginx abuse with the actual config I use.
Self-Hosting ntfy: Push Notifications Under 50MB RAM
A complete guide to setting up ntfy on a 1GB Debian Lightsail instance with Nginx, Let's Encrypt, WebSocket support, and Jenkins CI integration.
Nginx 101: how it actually works (from a newbie's perspective)
A ground-up explanation of nginx config files, server blocks, reverse proxying, SSL, and everything in between. Written after spending way too long debugging sites-enabled.