What alternatives to fcgi are there?

Question

CMS

I had to get acquainted with fast-cgi technology, write a simple CMS. And when everything started working, there was a desire to make the project more or less long-term. What are the protocols or technologies that threaten to replace fcgi in the niche of back-end servers? What is already in use?
Let me explain the essence of my project: there is cms on php, there is a configured nginx in front of it, it accepts php-fpm requests, and of course, the content is in the database. The difficulty is in the demolition of nginx and the database, since clustering is configured there, very complex and “unique”. My fcgi server completely replaces php-fmp, php code, related scripts, ie. anything that can query the database and the system.

Answer 1

There are at least SCGI and uwsgi, but they do not threaten to replace FastCGI.
It seems you have reinvented the wheel, but I didn’t really understand which one, either php-fpm or CppCMS.

Answer 2

Why alternatives?
Everything is working? Works.
What else is the problem?

Answer 3

If this is the question, then just make a wrapper for a piece of code that receives requests from outside, and add support for different modes / protocols to it. Take a list of more or less relevant protocols from the same nginx. For versatility (but, alas, not performance), add more cgi - it is everywhere.
PS. fcgi is an old proven productive solution, I doubt that in the near (or not very near) future something will become more popular and productive.