✓ UFW OS-level firewall
✓ AWS Lightsail cloud firewall
✓ Fail2Ban brute-force protection
✓ HTTPS via Let's Encrypt
✓ HTTP → HTTPS redirect
✓ API rate limiting (10 req/s)
✓ Per-IP connection limiting
✓ PHP / WordPress exploit blocking
✓ Bad bot detection & blocking
✓ Backend isolated to 127.0.0.1
✓ TLS + HTTP security headers (HSTS, XFO, nosniff, etc.)
✓ CSP / CORS / cookie strategy (Step 17 — app layer)
✓ Frontend + API audits (npm/pip audit, no secrets in client)
✓ server_tokens off
✓ SSH key-only login
✓ Root SSH login disabled
✓ Automatic security updates
✓ Fail2Ban SSH + NGINX jails