Distill

Reverse engineering specs from code is harder than it looks because you have to decide what's a domain rule versus what's just how someone happened to implement it. This skill handles distillation: you point it at existing code and it extracts Allium specifications by filtering out implementation details. The core trick is asking "would a product owner care about this?" for every line. Things like "expires in 7 days" matter, but "uses Redis" or "32 byte tokens" usually don't. The guide is thorough on scoping decisions, which matters in monorepos where you might only want to specify one service. Includes practical tests like "could this be different while still being the same system?" to separate means from ends.