ReactiveX is a great tool for writing asynchronous and event-based programs. The documentation is great and the library is well-designed. I have used ReactiveX to write several small and medium-sized applications. The library is very flexible and the API is easy to learn. There are several things that I dislike. Sometimes the API is a bit too much for beginners. I would like to see some examples of how to use the library. I would also like to see more functional programming examples. As a programmer, I have used the ReactiveX library to write various applications. I have found that ReactiveX is very flexible and has helped me write asynchronous and event-based programs.