Document GitLab.com puma request timeout

doc/user/gitlab_com/index.md

@@ -474,6 +474,10 @@ More information on this particular change can be found at
 of proposed changes can be found at
 <https://gitlab.com/gitlab-com/infrastructure/-/issues?scope=all&utf8=%E2%9C%93&state=opened&label_name[]=database&label_name[]=change>.
 
+## Puma
+
+GitLab.com uses the default of 60 seconds for [Puma request timeouts](https://docs.gitlab.com/omnibus/settings/puma.html#worker-timeout).
+
 ## Unicorn
 
 GitLab.com adjusts the memory limits for the [unicorn-worker-killer](https://rubygems.org/gems/unicorn-worker-killer) gem.