[geerlingguy]

Something's wrong with either the site architecture (too many modules), the web services used on the front end (something calling a web API on front or backend?), or the infra (slow MySQL?).

I've built some substantial D7 sites and have completely uncached page response times in the median of 100-300ms. Slow, sure, but anything over 1s and I figure out what's causing such abysmal performance.

With PHP 7 on a standard D7 site, those times are down sub-200ms.

And these are sites with over 100 contrib modules, usually 20-30 extra custom modules, and at least a million+ (Mostly anonymous, so those are cached) page views per day.