Old problems and new(?) physics: non-leptonic kaon decay and the Delta I=1/2 rule

I will review the status of our understanding of non-leptonic kaon decay — a classic problem that was born, grew up, and has matured alongside the Standard Model and the quest for new fundamental physics. Beyond state-of-the-art quantitative results, I will focus on a strategy to understand the mechanism responsible for the Delta I=1/2 enhancement, that brings together a large toolset of field-theoretical methods. Our most recent results, based on large N techniques, also allow for additional insight into light meson dynamics.