How to properly organize partial dynamic caching in nginx?

Question

Nginx

The task is as follows, you need to cache pages at the nginx level, with the exception of some blocks, the wordpress engine, the nginx + php-fpm stack.
reason, huge loads after 1000req/s , php-fpm starts loading percent at 100%. Change WordPress itself, plugins, etc. almost no longer possible, a well-established site with a lot of traffic.
Tell me, is this even possible? If so, where to dig and where to spy? Unfortunately google didn't help much.
Thank you!

Answer 1

Without changing the code of the site will not work.
You can, for example, cache pages, and load changeable blocks using JS. This, of course, will require a change to the site, and may not be as effective as it is. there will be quite a few requests, although each will be easier than a page request, if implemented correctly.
But it's better to cache where you can correctly invalidate the cache, not stupidly by ttl, i.e. at the application level. There are a lot of solutions for caching of varying degrees of sophistication for WP. You have to choose the right one and set it right...