Layered Design, Layered Trust: How a Designer Started Shipping Production Rails

Her first PR added 7,158 lines, deleted 1,920, and touched 153 files of a production Rails app. It shipped a token-based design system, a 28-section component catalog, and a full visual overhaul. The designer was the primary author. The pattern is three layers deep, borrowing from layered Rails: a mechanical floor of Tailwind tokens, a middle layer of named partials, and a natural-language contract in CLAUDE.md at the top. An engineer and a designer tell the story together — real code, real prompts, and what broke the first time.