Hundreds of books are available to help you write Ruby source code and there are multiple large disciplines about how to structure the concepts within your code. But when you execute your code it ceases to be source and begins life as a unix process alongside other processes on a piece of hardware somewhere in the actual world. I'll walk us through how to reason about your process, how to know what it's doing and what resources it's using and how to determine whether it's healthy. We'll learn about what you can add to your source to make debugging easier, how to debug your code as if it were merely a C program, and what kinds of unique behaviors MRI, Rubinius, and JRuby have that are distinct from processes written in other languages.