In 2013 the Reactive Manifesto was published, establishing a set of properties for modern systems: responsive, resilient, elastic and message driven. In 2020, the Reactive Foundation published a set of principles and patterns for Reactive systems. In this session we will look what reactive architectures are and what have we established about how to succeed at building reactive systems. Our focus will be on how the properties we desire for reactive systems push us towards certain principles of software design. We will dig into how to achieve the properties of reactive architecture and learn how message passing is the key that unlocks isolation and with it resilience and elasticity. We will understand what it takes for message passing to achieve this, the key principles and design patterns that you need to know and apply. Along the way we will draw from the works of folks spanning the history of actor models, autonomous and reactive computing from Carl Hewitt to to Pat Helland and Jason Boner. By the end of the session you should have an overview of the current best practice ideas you need to succeed at reactive programming. Check out our new channel: NDC Clips: @ndcclips Check out more of our featured speakers and talks at https://ndcconferences.com/ https://ndcoslo.com/