Building a Concurrent TCP Chat Server in Go (NetCat Clone)

In this project, we built a simplified version of the classic NetCat ("nc") tool — a TCP-based chat server that allows multiple clients to connect, send messages, and interact in real time. The goal was not just to recreate a chat system, but to deeply understand: TCP networking Go concurrency (goroutines & channels) State management in concurrent systems Client-server architecture At its core, the system needed to: Accept multiple client connections Allow clients to send messages Broadcast messages to other clients Track when users join or leave Handle unexpected disconnects (like Ctrl+C) This introduces a key challenge: «Multiple clients interacting with shared state at the same time.» TCP Server Basics The server listens for incoming connections using: listener, _ := net.Listen("tcp", ":8989") Then continuously accepts clients: for { conn, _ := listener.Accept() go handleConnection(conn) } Important concept: "Accept()" blocks until a client connects Each client is handled in a separ