This document provides an overview of microservice architecture using CQRS (Command Query Responsibility Segregation) and Event Sourcing patterns. It defines CQRS as separating the write and read functions of an application. Event Sourcing records all state changes as a series of events rather than just the current state. The benefits include scalability, simplicity, flexibility and a business focus. Popular companies using this architecture include those needing cost-effective scaling like microservices. The author provides resources and advocates for CQRS and Event Sourcing to solve common architectural challenges.