Load Balancers Explained

When your application starts getting traffic, one server is never enough. At scale, distributing traffic correctly becomes one of the most important architectural decisions. In this article, we’ll break down: What a load balancer is Why it’s needed Types of load balancers Algorithms used Health checks Real-world architecture patterns The Scaling Problem Imagine: 1 server 500,000 users Peak traffic Even if the server is powerful, it will eventually hit limits: CPU saturation Memory exhaustion Network bottlenecks The solution is horizontal scaling. But how do users know which server to hit? That’s where load balancers come in. What Is a Load Balancer? A load balancer is a system that: Accepts incoming client requests Distributes them across multiple backend servers Ensures no single server is overloaded Basic architecture: Clients → Load Balancer → Server Pool Why Use Load Balancers? 1️⃣ Scalability Add more servers without changing client logic. 2️⃣ High Availability If one server fails