Ruby has never been renowned for its performance. We choose to love Ruby for its more admirable traits, like simplicity and expressiveness. But it turns out that we can have the best of both worlds by kicking the single-threaded model to the curb and using tried and true concurrency abstractions. We will take a look at the building blocks Ruby offers for concurrency and how Rubyists have used these to build scalable, performant libraries just dying to be used. You’ll walk away with an understanding of concurrency and how you can leverage it in your applications today.