Are you the kind of programmer who prefers to never see the same code in two places, or do you make liberal use of copy/paste? Many developers swear by the Don't Repeat Yourself (DRY) philosophy while others prefer to Write Everything Twice (WET). But which of these produces more maintainable codebases? I've seen both of these approaches lay waste to codebases and I have a new ideology I would like to propose to you: Avoid Hasty Abstractions (AHA). In this keynote, we'll talk about abstraction and how you can improve a codebase by applying and creating abstractions more thoughtfully as well as how to get yourself out of a mess of over or under-abstraction.