What is horizontal scaling and how was it applied?

Horizontal scaling is an approach to increasing system performance by adding more nodes (servers) to a cluster, rather than increasing the resources of a single server (vertical scaling).

Applications:

• In web applications, new application servers are added behind a load balancer to handle more requests simultaneously.
• In databases, sharding is used — distributing data across different servers.
• In the frontend, CDN can be scaled to deliver content to users faster.

The advantage of horizontal scaling is flexibility and fault tolerance, as the load is distributed among many nodes.