Rails is incredibly powerful because of its abstractions. For years, developers have been able to hit the ground running and be productive without having to know the in's and out's of the core computer science concepts that fuel this framework. But just because something is hidden away doesn't mean that it's not worth knowing! In this talk, we'll unpack the CS fundamentals that are used in the Rails router. Together, we'll demystify the graph data structure that lies under the hood of the router in order to understand how a simple structure allows for routing to actually work in a Rails app.