RxJS has become almost a standard in the emerging reactive Front-End world. If you're not using it right now, you probably played with a few operators. In the talk we're going to rewrite RxJS from scratch, seeing behind the curtains which are the core components and the ideas of the library. You'll see how to build Observables, Subscriptions and Operator, then we'll introduce Schedulers and how they're used in RxJS. If you fancy Reactive Programming or simply you want to learn something new then... this talk is for you!