A chat system is one of the first network programming exercises. You must be trying to satisfy requirements that are beyond basics. Assuming persistent chat rooms are required, do you really need anything beyond some tables in a relational database that model chat rooms/chats?
This isn't talking about a hello world level application this is talking about an application managing complex state at scale. Maybe some bytes sent between points representing audio at the same time across several different sessions. I assure you that the problem set slack, people working on Fortnite servers etc is not the same problem set as a network programming illustration even if it's the same start point.
