Case Study: Amazon's Two-Pizza Teams and Service Ownership

One of the biggest challenges in building microservices isn't technical. It's organizational. You can split an application into dozens of independently deployable services, but if every change still requires coordination between multiple teams, you haven't achieved much independence.

Amazon recognized this problem as its business and engineering organization grew. Instead of focusing only on breaking large applications into smaller services, Amazon also changed how engineering teams were organized.

This led to two closely related ideas: Two-Pizza Teams and "You Build It, You Run It." Together, these principles helped Amazon align service architecture with team ownership, enabling teams to develop, deploy, and operate their systems with greater autonomy. In this chapter, we'll explore how these principles work, why they matter for microservices, and how to apply them.