Emil Kowalski has trained thousands of developers to build interfaces that feel right through his animations.dev course, and this skill distills that entire philosophy into Claude. It reviews your UI code using specific before/after tables, catches common animation mistakes like using ease-in or animating high-frequency actions, and applies Emil's framework for deciding what should animate and how fast. The skill enforces concrete rules like keeping UI animations under 300ms, using custom easing curves instead of CSS defaults, and understanding that perceived performance matters as much as actual speed. It's particularly sharp on the invisible details that compound into interfaces people love without knowing why.
npx skills add https://github.com/emilkowalski/skill --skill emil-design-eng