A reverse proxy forwards requests to a single backend server, while a load balancer distributes requests across multiple backend servers. Load balancers include health checks and various distribution algorithms like round-robin or least connections.

First install certbot, then run ‘certbot –nginx -d yourdomain.com’. The generated certificates will be placed in /etc/letsencrypt/live/yourdomain.com/. Our SSL configuration uses the standard Let’s Encrypt paths for maximum compatibility.

Security headers protect against common web vulnerabilities. X-Frame-Options prevents clickjacking, X-Content-Type-Options stops MIME-type sniffing attacks, and CSP helps prevent XSS attacks. These headers are essential for production websites.

Set long cache times (1 year) for versioned assets like CSS/JS with hashes in filenames. Use shorter times (1 day) for images and other static content. Always use versioning or cache-busting for files that change frequently to avoid stale content issues.

Use ‘nginx -t’ to test configuration syntax. Check error logs at /var/log/nginx/error.log for detailed error messages. Common issues include missing semicolons, wrong file paths, port conflicts, and directive placement errors. Always backup working configs before making changes.