UI Engineer II

The Merchant Experience domain's mission is to craft seamless experiences so every Mollie moment feels intuitive, secure, and supportive. We are hiring UI Engineers across the domain. As a UI Engineer, you bridge the gap between platform capabilities and the teams that rely on them, working across the frontend, backend and infrastructure as needed. This is not a role where you ship one feature and move on. You will have real ownership, real visibility, and the chance to do work that matters at scale.

Responsibilities

Craft seamless experiences so every Mollie moment feels intuitive, secure, and supportive; Bridge the gap between platform capabilities and the teams that rely on them, working across the frontend, backend and infrastructure as needed; Scale the mobile app architecture to support growing user demand, with a focus on quality and long-term maintainability; Accelerate the app release cadence by improving and owning the release process, moving from bi-weekly to weekly deployments; Build reusable patterns, tooling, and documentation that allow engineers across all domains to contribute to the mobile app without needing deep mobile expertise; Support debugging and feature delivery for teams across Mollie, acting as a platform partner to product teams who depend on the AppCore foundations; Own and evolve the Mollie UI design system, ensuring consistency and quality across web and mobile; Rebuild and improve the mobile navigation architecture, covering both the system design and the visual experience; Improve app accessibility in line with compliance standards; Strengthen testing practices and automation to raise reliability and reduce regressions across the app; Own the Upsell infrastructure and in-app messaging that enables targeted campaigns to drive merchant engagement and product activation

Requirements

4 or more years of experience developing mobile apps and web applications, with solid hands-on React and/or React Native experience and a genuine, deep understanding of JavaScript fundamentals at a low level; Experience with CI/CD pipelines and app release processes; Comfort working with native browser APIs and language primitives, and enough CSS confidence to implement interfaces using design system components; A track record of building or maintaining products at medium to large scale, where code quality, reliability, and performance actually matter, including experience with test-driven development and REST API design; A product-first mindset with end-to-end ownership, from design iteration through to delivery with a focus on user experience and measurable outcomes; A generalist mindset with strong communication skill; Always Be Shipping mindset: consistently delivering value to customers, where speed and quality go hand in hand

Benefits

Noise cancelling headphones; MacBook; Birthday off; Complimentary baby days; 20 days working from abroad; 22 holiday days; Commute allowance; Work from home budget; Bike lease plan; Internet allowance; Lunch voucher; Wellbeing program; Pension contribution; Health insurance; Bonus scheme; Equity plans; Referral bonus; Learning platform; Mentor program