Have you had experience working with reactive libraries and technologies in your projects?

Yes, in Java projects I have used reactive libraries such as Reactor and RxJava. They allow working with asynchronous data streams, handling events and errors in a reactive style, which improves the scalability and responsiveness of applications.

Example of using Reactor to create a simple reactive stream:

Flux<String> flux = Flux.just("A", "B", "C")
    .map(String::toLowerCase)
    .filter(s -> !s.equals("b"));

flux.subscribe(System.out::println);

This code creates a stream of three elements, converts them to lowercase, and filters out the element "b".