Using Varnish for Drupal 8 | Drupal 8 and Mobile Apps Development Team (anyforsoft.com)
Many web developers praise Drupal 8 for its excellent performance. Nevertheless, this engine is not efficient enough when serving a massive influx of user requests. In this case, it is not uncommon for expert developers to employ an aid from a caching proxy server. Usual examples of such solutions are Apache and nginx.