All abstractions are leaky, and we tend to think of that as a bad thing. But sometimes it’s useful to be reminded of the implementation details. Knowing how something works under the covers often makes it a lot easier to use the abstraction. Take regular expressions - very powerful, yet very hard to use - arguably a write-only language! But once you know how the abstraction works, reading and writing a regular expression becomes a lot easier. In this talk, we’ll take a look at some popular, perhaps overlooked, abstractions, see how they work, and see how understanding the level below an abstraction makes you a better developer.