Summary
Improving your website's performance to load in less than 1 second requires optimizations at multiple levels. These include server-side, front-end, and network performance.
Use Gzip or Brotli compression for HTML, CSS, and JS. Use HTTP/2 or HTTP/3 - These protocols allow multiplexing and reduce request overhead. Use Real User Monitoring (RUM) with Cloudflare or New Relic.