The world of business applications is changing. Monolithic applications are being broken up into smaller services. The inherent symmetry of CRUD operations has been bifurcated by the emergence of GraphQL and its discrete input and output types. Enterprise users are expecting their interfaces to have capabilities present in consumer apps they use in their personal lives. It is time for business application architectures to evolve.  The properties of a reactive system (responsive, resilient, elastic and message driven) are aligned with what application developers strive to achieve in their work. Borrowing ideas from Event Sourcing and CQRS, we will go over in depth the design and implementation of an application that is helping power Netflix’s studio. We will discuss how each of the properties of a reactive system is a desired property in modern cloud-based architectures. GraphQL, tracking data provenance, and observability will all be discussed.