In this talk, we will explore the ever-present value of Event Driven models, what the difference between an event log and an event model is and how Promise theory plays into this programming paradigm. We will also explore the value of Event Sourcing as well as Command Sourcing related explicitly to historical state management and when to and when not to use Event Sourcing or Command Sourcing vs. CRUD. Another topic ripe for discussion, as they go hand in hand, is how an Event Driven model provides a natural audit log as well as handling data projections by way of CQRS and Fast Data Streaming. Required knowledge General understanding of the basics of programming and state management is desirable. Learning objectives Attendees will walk away with an understanding of Event Driven modes and how they work in distributed systems couched in Promise theory as well as how to project data via CQRS and Fast Data streams. Duncan DeVore is co-author of "Reactive Application Development", Principal Systems Engineer at Lightbend, open source developer and frequent speaker. He has been an avid Scala developer since 2009, holds three patents for software design and led the release of one of the first large-scale Reactive applications in 2012.