Ivan Nemytchenko's unfinished book on Rails patterns. Referenced in the Q&A of The Curse of Service Object: an audience member asks whether the talk's approach extends the patterns from this book, and Ivan confirms — the talk is the evolution of what he wrote there, and he intends to rewrite it. The book introduced 'shapes' (essentially form objects), a concept Ivan no longer thinks was well-named. He plans a separate talk on forms as a continuation.