Track_1
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 @theme tokens and @layer base defaults. A middle layer of named, discoverable partials. A natural-language contract in CLAUDE.md at the top.
An engineer and a designer tell the story together. We show real code, real prompts, and what broke the first time. You leave with a pattern you can drop into your Rails app, and a sharper question: who on your team could be shipping if the harness were better?
The designer was the primary author.
The pattern is three layers deep, borrowing from layered Rails. A mechanical floor of Tailwind @theme tokens and @layer base defaults. A middle layer of named, discoverable partials. A natural-language contract in CLAUDE.md at the top.
An engineer and a designer tell the story together. We show real code, real prompts, and what broke the first time. You leave with a pattern you can drop into your Rails app, and a sharper question: who on your team could be shipping if the harness were better?
About_the_speaker
Alicia Rojas
Software developer · Telos Labs
Software developer, musician, and natural resources engineer from Chile. Builds products with social and environmental impact. Currently focused on harness engineering: the scaffolding that makes AI agent output trustworthy, so teams garden systems instead of line-reviewing code.
Arely Rivera
Lead Product Designer · Telos Labs
Lead Product Designer at Telos Labs. Works end to end: research, design, AI-assisted code, and measure. Focused on the harness that lets designers contribute trustworthy production code alongside engineers.