Circuit UI is the design system used to build a wide variety of web applications for SumUp, while providing a consistent, accessible, and performant user experience to its users.
The problem was that when I joined there were only color palette, text styles, and some effects well‑defined as global styles. Everything else wasn't. Components would be designed locally for an individual project and then copy‑pasted into every next project where they were needed. Over time a lot of inconsistencies built up.
Me and Boris - another Product Designer working in‑house, made it our initiative to sort that out and began our work starting with the icon library. We streamlined the most basic components and then went on to incorporate them into the more complex ones according to the atomic design principles.
6 months later we had a design component library that was in line and ahead of the coded library, so we started planning into the future and across platforms. This is when a dedicated Systems Designer joined the company and led this work from then on.