Emil Kowalski
Build an animation from scratch, making the decisions in the order that determines whether it feels right — should it animate at all, what purpose, which tool, which properties, which curve and duration, how it interrupts, how it exits. Writes the implementation. Use when asked to animate something, add motion, make a component feel alive, or build a transition. For critiquing existing motion use review-animations; for auditing a whole codebase use improve-animations.
Build animations in React Native and Expo, making the decisions in the order that determines whether they feel right — should it animate, which thread it runs on, which properties, spring or timing, how the gesture hands off, how it degrades. Writes the implementation with Reanimated, Gesture Handler, Expo Router and expo-haptics. Use when animating anything in an Expo app, adding gestures, sheets, screen transitions, press feedback or haptics, or fixing motion that stutters on device. For web animation use animate.
Keep web animations inside the frame budget — animate composite-only properties, keep motion off the main thread when the page is busy, and find the cause when an animation drops frames. Covers the layout/paint/composite pipeline, cheaper property swaps, CSS vs WAAPI vs requestAnimationFrame, Framer Motion's hardware-accelerated path, React re-rendering per frame, inherited CSS variable recalculation, blur cost, and when `will-change` actually helps. Use when an animation is janky, choppy, stutters, or drops frames; when choosing which property to animate; when deciding between CSS and JS animation on performance grounds; or when reaching for `will-change` or GPU layers. For choosing easing, duration, or whether to animate at all use animate; for reviewing motion as a whole use review-animations.
Sharpen motion language so animation choices feel deliberate and consistent.
Apple's approach to interface design and fluid, physical motion, translated for the web. Use when building or reviewing gesture-driven UI, spring animations, drag/swipe/sheet interactions, momentum and interruptible transitions, translucent materials and depth, typography (optical sizing, tracking, leading), reduced-motion, or the design foundations (feedback, spatial consistency, restraint) behind Apple-style interfaces.
Guide to Sonner, the React toast library — install and wire up the Toaster, pick the right toast() call, promise and loading toasts, updating, dismissing and persisting toasts, styling, theming and icons, positioning and multiple toasters. Use when working with Sonner or troubleshooting it — toasts that don't appear, appear twice, lose their styles, ignore Tailwind classes, sit behind a modal, or don't follow dark mode.
Stress-test UI with worst-case data behind a demo toggle, then report what broke and how to fix each edge case.
Coordinate several elements that animate together — decide what moves, in what order, how much they overlap, and what stays still — so a group reads as one intentional motion instead of a pile of separate animations. Use when building or fixing a staggered list, a hero entrance, a view swap inside a container, a multi-step flow, an element leaving while its siblings close the gap, a morph between rich states, or any interaction with several moving parts (icon + background + lines, panel + conten
Emil Kowalski's design-engineering philosophy for UI polish, components, animation, and production-ready frontend craft.
Find high-conviction opportunities for useful interface motion while rejecting animation that adds noise or slows users down.
Build drag, swipe, and sheet interactions that track the finger 1:1 and stay interruptible. Use when building or fixing anything the user drags, swipes, flings, holds, or dismisses with a gesture — drawers, sheets, swipe-to-dismiss toasts and cards, drag-to-reorder, pull-to-refresh, hold-to-confirm — or when a gesture feels laggy, disconnected from the finger, jumps on release, or can't be caught mid-animation. Triggers on — gesture, drag, draggable, swipe, swipe to dismiss, fling, momentum, vel
Survey a codebase's animation and motion code as a senior motion advisor, then produce prioritized audit and self-contained implementation plans. Read-only on source code - it plans improvements, it does not apply them. Use when the user asks to improve animations, audit motion, make an app feel better, or wants a roadmap of animation fixes rather than a review of a single diff.
Make a web app feel native on a phone with CSS and meta-tag fixes for touch, viewport, scroll, safe areas, inputs, and PWA polish on real hardware.
Choose an opinionated, trusted library for common frontend tasks including components, motion, charts, interaction, state, and styling.
Build multiple genuinely different UI variants behind a visual picker so the strongest direction can be evaluated and promoted.
Find the animations an interface doesn't need and remove them — motion on keyboard actions, high-frequency surfaces, functional data, and decoration with no purpose — then clean up what they leave behind. Edits code, but only to subtract; it never adds or retunes motion. Use when the user says the app "feels slow", "has too much animation", "feels over-animated", wants to "tone down the motion", or asks what animations to remove. For finding places that should animate, use find-animation-opportunities; for fixing animations that should stay, use improve-animations or review-animations.
Review animation quality, timing, and motion consistency with a production-critical eye.
How to write modern Swift well — modeling with value types, Swift 6 data-race safety and approachable concurrency (@concurrent, main-actor-by-default, actors, task groups), protocols and generics (some vs any), API design, performance and ARC, Swift Testing, macros, and the modern language features agents don't know about yet. Use when writing, reviewing, or migrating Swift, or when a concurrency error, a hang, a data race, a retain cycle, or a performance problem needs fixing.