We are currently creating a plugin for internal company use which requires us to do a lot of Ajax requests for get and post, as its requirements are no refreshing of pages as possible. The plugin is use for internal analytics.
Does it affects website performance if we are planning to have 30 or more?
In very broad terms, each ajax request takes the same amount of "effort" by the server to process like a full page load. From this perspective, 30 AJAX requests instead of one page load sounds like a very bad idea. It all also depends on the frequency those requests are being "fired", if it happens every second it is bad, if only when a user does some action, it might not be optimal, but not the end of the world.
Of course, if this is a requirement, it can be solved by using a stronger web server, which in an intranet enviroment should not be a very expensive idea.
What you should do in any case, is to try to minimize the number of requests, for example by combining several of them.
