More than 30 sites (domain + subdomains) on gino. How to reduce the load on the server CPU (jino)?

Question

Joomla

Greetings. There are sites of free ads, in the amount of more than 30 pieces. This year, the sites started to gain momentum and I encountered unwanted loads on the server. At the moment it is 20-30%% to a strict limit. But this is only the beginning. In the near future, the loads will rise by about 10 times or more, given the fact that there will be more and more users. Fortunately, the target audience is limited (1 + -0.1 million people). How can you optimize Joomla? Just keep everything to a minimum.
The site uses the dj-classifieds bulletin board component.

Answer 1

Configure, for example, caching so that the database is not pulled once again, the output is not re-formed every time with every request.
But this is savings on matches, given the number of sites.

Answer 2

And it turns out that it doesn't. 30 sites on one server? Yes, and a million users. Here you first need to distribute the load between servers or rewrite everything on a lightweight framework. So either buy a more expensive plan, or rewrite everything.

Answer 3

This is complex work. There cannot be a clear answer here.