I was reading once that the Stack Exchange sites are using caching heavily.
Checking the HTML source of a site, when logged-in and when being an anonymous visitor, shows in both cases (example):
<div class="user-action-time"> asked <span title="2019-08-11 16:43:43Z" class="relativetime">3 mins ago</span> </div>
Obviously the "3 mins ago" part is rendered serverside, which means from my perspective, that it is not cached.
Do I misunderstand the "caching mechanism"? Maybe different parts of the site are cached and put together? I see caching as a fixed information, not a newly generated piece of information.