Fibers have long been a neglected corner of the Ruby core API, have never really seemed to deliver on their promise of lightweight concurrency, and remain relatively little explored. In this article I’ll explain how fibers work from the point of view of a concurrent Ruby application written using Polyphony. I’ll give an overview of fibers as concurrency constructs, and discuss how Polyphony harnesses Ruby fibers in order to provide an idiomatic and performant solution for writing highly-concurrent Ruby apps. Read on…