Scaling From Zero to Millions of Users

Overview

The following text is from “System Design Interview” by Alex Xu.

The following techniques can be applied to scale a system to support millions of users:

• Keep web tier stateless
• Build redundancy at every tier
• Cache data as much as you can
• Support multiple data centers
• Host static assets in CDN
• Scale your data tier by sharding
• Split tiers into individual services
• Favor asynchronous communication (e.g., message queues)
• Monitor your system and use automation tools

Simple App

Example scalable design