ESI, as it's already been pointed out, is one big way. I tend to not like requiring JS to make my pages usable, as not everyone has JS turned on and it's abili

ESI, as it's already been pointed out, is one big way. I tend to not like requiring JS to make my pages usable, as not everyone has JS turned on and it's ability to work correctly in non-mainstream browsers, while improving, can be spotty. Really, if most pages on your site are identical for every user, sans their name + avatar at the top, it's worth figuring out a strategy to serve the page content from disk and swap in the dynamic parts easily without hitting your app layer.