Ruslan Isay, a project manager from i20.biz company, gave a presentation about their experience with Drupal, Nginx, and Varnish. Their website has over 500,000 pages and 800,000 registered users. They use Varnish for caching and Nginx for file storage and load balancing. They implemented edge side includes (ESI) to cache dynamic content and purge caches when content changes. Custom modules integrate ESI and handle cache expiration.