The Internet is asynchronous, people are asynchronous, the universe is asynchronous. They are now and they always will be. Writing applications which deal correctly with asynchronous data is difficult. Or at least it was. Microsoft open sourced ReactiveX in 2010 to make what used to be some of the hairiest kinds of coding almost easy. The project was so well received that it has been ported to nearly every major programming language. Versions of ReactiveX exists for .NET, JavaScript, Java, Scala, Clojure, C++, Ruby, Python, Groovy, JRuby, Kotlin, and Swift. The project is open source and community maintain with corporate backing from the likes of Microsoft and Netflix. Microsoft created the ReactiveX, then called reactive extensions, from the burnt out remains of Project Volta. Project Volta's goal was to extend .NET's to run both on the server and in the browser. A compiler would decide which parts were best to put where. It essentially was the Meteor framework in 2007. In this talk we will take a deep look at ReactiveX. We will use code samples to show how things are done before and after ReactiveX. The code will be in C# and JavaScript. We will see how ReactiveX makes our lives as developers easier and our code more reactive.