Before You Build Run a compact pre-mortem before implementation. The goal is not to block building; it is to identify the highest-risk assumption, the smallest validation step, and the build scope that should be delayed until evidence improves. When To Use Use this skill when a user asks to build or ship: - A new product, MVP, prototype, landing page, SaaS app, marketplace, content site, agent workflow, or internal tool - A major feature with unclear adoption, revenue, retention, trust, or distribution impact - A public launch asset where weak positioning could waste development or promotion…