title: Does it make sense to use Reactive Programming from a performance standpoint when not dealing with slow IO?
body: <p>Using Reactive Programming with, for example, Java and <a href="https://projectreactor.io/" rel="nofollow noreferrer">Project Reactor</a> makes a lot of sense when dealing with slow IO, or when you want to stream back results to the end-user. The code you write tends to look cleaner - similar to when using Functional Programming and Streams - but you're also forced to write things differently, which makes life harder for programmers new to the concept.</p>
  
  <p>I was wondering whether it makes sense to use from a performance standpoint in general? In case of a program without any I/O apart from some screen output (like calculating infinite PI numbers, or Fibonacci sequences), won't it just slow down your calculations? Or do the gains in your code cleanliness make that a small price?</p>