scary sounds. You mean some sort of distributed server, where the parts communicate with each other in client-server? Still sounds scary. Well, okay.
If for performance, Java is likely to win php and python. Scripting languages are less efficient compiled. Generally choose php and python to write the server - bad idea, they are not in order and it will not open and will not cover. If you want to write efficient server, you in C++, Golang, Rust, although Java will do. These languages all of the tools to do this and libraries. Many servers are already written.