Design Reddit: Scalability and Performance

To meet the demands of a web-scale system, we employ multiple strategies to scale horizontally and maintain high performance:

1. Horizontal Scaling of Stateless Services: All our core services (Auth, Post, Feed, etc.) are designed to be stateless and thus can run behind load balancers with multiple instances. If user traffic increases, we simply deploy more instances of each service. Because state (data) is in the databases and caches, any service instance can handle any request for a given type