Sebastian Zelonka

UI Engineer

Pixel-perfect, performant, and accessible products on the web.

Design background.
Engineering mindset.

I’m Sebastian, a UI engineer from Buenos Aires with more than 14 years of experience creating digital products. I started in product design and gradually moved closer to the code that brings interfaces to life.

Today I work at the intersection of design, product and engineering, building accessible interfaces and design systems that help teams move together.

More about me

Selected experience

Over 14 years moving between design and engineering—turning product decisions into accessible, scalable interfaces.

  • 14+years in digital products
  • 03disciplines connected
  • ∞details that matter
  1. ank

    Frontend Developer · Senior UX Designer

    Made the jump from product design to frontend development, creating shared components and helping build the QR payment experience from its earliest flows through implementation.

    • React Native
    • GraphQL
    • TypeScript
    • Jest
  2. Increase

    Senior UX Designer

    Rapid prototyping and design system foundations, creating the shared language that helped product and frontend teams move together.

    • React
    • Styled Components
    • Storybook
Explore the full career

Latest thoughts

  • Case study
    Kibble Design System

    How I helped take Kibble, Vetsource's design system, from an empty repository to a component library used across product teams.

  • UX
    Notes on Creating and Maintaining Successful Design Systems

    Some notes, links and thoughts on creating and maintaining design systems

  • Career advice
    New Site

    During the last few months I had more free time, spent it learning React and this new site is the result.

All thoughts