This talk is about going back to the basics, when Reactive Programming was not a buzz and not used in the Enterprise Arena. There will be moments when you will regret being here, but then we will present you with the Beauty of the Seventies. This talk intends to make you travel through time, experiencing how things were done back then. From the Beauty of the Seventies we will move straight to the GoF Observer pattern, which has been implemented over and over again with Publish / Subscriber mechanisms. That will depict the foundations of what we have seen with Functional Programming, Reactive Programming, FRP and Reactive Streams. Although all that sounds interesting, it’s not our last stop. We still have to go over Java 9 and Spring Web Reactive Framework. It embraces Reactive Streams and Reactor, by defying the challenge of switching from imperative-style to non-blocking logic. It might be seem by some as shiny and new, but it’s based on a well established idea that has been helping us for more than 40 years.