How many simultaneous connections will the server pull on NODEJS + RHEL6?

Question

API

On NODEJS (on RHEL) a simple server-API is written (the disk is virtual but large), it receives JSON objects, they contain pieces of files in base64.
The pieces are decoded, concatenated and put on the nodejs server.
Also, the files available on the nodejs server are taken and removed from the server.
Files ranging in size from 1 to 20 mb, the size of file pieces in JSON objects is up to 1 mb.
The nodejs server has the pm2 package installed - the process manager.
How many concurrent connections can this nodejs server handle?
And what can be done so that the server does not lie down from a large number of connections?

Answer 1

So that the server does not lie down, it is necessary to design horizontal scaling.
And that means a lot of servers.
PS This is not a "hard question"