To skip to actual technical content go to slide 71 https://speakerdeck.com/schneems/threads-arent-evil?slide=71 the first slides make no sense without narration.
Okay, so threads are pretty evil.
But they are also useful, and given the right development patterns: not impossible to work with.
In this talk you'll look at some real Ruby libraries where threads were applied to accomplish otherwise impossible tasks. We'll look at re-writing a synchronous library to support parallel execution for performance gains. We'll also talk about the operating system internals of exactly what makes a thread a thread.
If you're not comfortable with the "T" word (threads), this talk is the perfect introduction to practical concurrent programming in Ruby.