Current stance (June 2026): The AI industry is best understood as a stack of six layers, each with different economics, different defensibility, and different implications for someone who works at the business layer. The bottom of the stack (silicon, cloud) is where value is captured today. The top (applications, business domains) is where value will accrue tomorrow — but only for those who understand that distribution and domain expertise matter more than model quality. This document is my attempt to build a mental model of the whole thing, layer by layer, so I can think clearly about where I sit and what comes next.