# Building a Non-Blocking Multithreaded TCP Server in C++

Most developers spend their time building APIs, dashboards, and CRUD systems. But at some point, I wanted to go deeper — to understand how servers actually work at a lower level. So I built a simple non-blocking multithreaded TCP server in C++. Why this project? This wasn’t about building something production-ready. It was about learning: How TCP servers handle multiple clients What “non-blocking I/O” really means in practice How multithreading impacts performance and scalability The hidden complexity behind backend systems Core Concepts 1. TCP Sockets The foundation of communication between client and server. Using low-level socket APIs gives full control — and full responsibility. 2. Non-Blocking I/O Instead of waiting for operations to complete, the server continues execution. This avoids: Blocking the entire process Wasting CPU cycles on idle connections 3. Multithreading Each connection can be handled independently, allowing multiple clients to interact with the server simultaneou