Customizing Drupal

There's a common saying among Drupal developers: "Every time you hack core, god kills a kitten", but what is the alternative to get 100% of the functionality you need without modifying Drupal core or contrib module? In this presentation I'll show you a few tips and general principles for getting what you want out of Drupal's APIs. There will be lots of examples from real-life cases, feel free to bring your own as well.