emil-design-eng
A skill from Emil Kowalski, design engineer at Linear and author of Sonner, the React toast library sitting above 13 million weekly downloads. It does not hand your agent a taste checklist, it hands it a thinking order: what this screen is for, which state it has to make legible, and only then which motion or spacing serves that. Most of the material covers animation and component design, extracted from his own open source libraries. **The repository holds a dozen skills, not one**, and most of them deal with motion. `animate` sets up an animation with the right curve, duration and properties; `find-animation-opportunities` spots the areas of an interface that would gain from moving; `review-animations` strictly reviews the existing ones and `improve-animations` ranks the fixes by priority; `animation-vocabulary` gives you the precise words to request motion from an agent instead of asking for something smooth. It answers the most common complaint about an app shipped by an agent: everything is clean, and everything is flat.
Strengths
- Written by a practitioner whose work you can audit: Sonner and Vaul are open source and readable
- Carries the upstream reasoning (intent, state, hierarchy) where other design skills start from the output
- Strong on motion and micro-interactions, a rare angle among design skills
Limitations
- Heavily React and web oriented, so it transfers poorly to native or to a non-web design system
- A single author personal skill, with no maintenance guarantee and no stable versioning
Best for
- Components that are technically clean but say nothing
- React front-ends where motion and state drive perceived quality
- Designers and PMs who want the agent to decide what to build before building it