The Actions and Filters API is what puts WordPress head and shoulders above its rivals.
We’ll start off the talk by touching briefly on what an action or filter is, how the WordPress core functions use them, as well as how to find obscure (and often overlooked) ones.
The meat of this talk, however, will focus on the unlimited potential for actions and filters. We’ll take a look at how plugin and theme authors use them, and cover best practices for including them in your own work. Finally, we’ll cover some extreme examples, like a completely action-driven “layout-first” theme and a template library that uses filters at the atomic level for ultimate control.