One of the most challenging aspects of building a distributed system is scaling it to handle different levels of user traffic. In this blog post, I will discuss some of the common techniques and trade-offs involved in scaling a distributed system from 1 to 1 billion users. I will also provide some step-by-step explanations for each scale.

1. Scaling from 0–1K,
   
2. Scaling from 1K -10K,
3. Scaling from 10K-100K,
4. Scaling from 100K-1M,
5. Scaling from 1M to 1B users

Twelve Factor App Methodology

The Twelve-Factor App methodology is a set of best practices for building and deploying cloud-native applications. It was developed by Heroku, a cloud platform as a service (PaaS) provider, and has since been widely adopted by organizations as a guide for building cloud-native applications.

The Twelve-Factor App methodology consists of 12 principles that are designed to help developers build applications that are easy to scale, maintain, and deploy in a cloud environment.