Frontend Developer

Zellerfeld is revolutionising the footwear industry with the world’s first 3D-printing technology for fully customizable shoes. Our goal is simple: printed shoes on every foot. We’re a passionate team of engineers, designers, and innovators, questioning the status quo and disrupting traditional manufacturing processes. Backed by founders, influencers, and celebrities who believe in our vision, we’re committed to making a lasting, positive impact—not just on the footwear industry, but on the world. Your Mission You’ll be part of a small team of software developers building the factory of tomorrow. Your job will be to refactor and optimize existing software and the development of new tools and services from footscan via production to the consumer. As a part of our development team, you will find solutions for problems you never heard of and extend your knowledge daily. What You'll Do Drive frontend architecture across our three product surfaces, making decisions about patterns, boundaries, and shared infrastructure that hold up over timeOwn features end-to-end: from the design conversation through implementation, production rollout, and the inevitable debugging session when something behaves differently on the factory floor than it did in stagingLead on performance, scalability, and observability. Core Web Vitals on the consumer side, realtime responsiveness on the hardware-adjacent side, and the instrumentation that lets us know which is brokenApply frontend security rigor. Not just "we use auth tokens," but a working understanding of XSS, CSRF, CSP, dependency risk, and the everyday vulnerabilities that ship to production when nobody's watchingNavigate ambiguity: translate vague product, hardware, or operational needs into technical direction, and know when to ship a fast solution versus invest in a durable oneCollaborate directly with hardware engineers on the production-side UIs and with operations on scanning and in-store experiences. The feedback loop is short and the requirements are realMentor other frontend developers, review code with intent, and help establish the engineering practices that scale with the team Your profile Senior-level React and TypeScript experience, with a track record of owning non-trivial frontend systems in productionDemonstrated ability to make architectural decisions about patterns, abstractions, and where to draw the line between shared and bespokeProduction debugging experience across the full path: browser, API contract, network, and infrastructure. You've been the person who actually found the problemPerformance and scalability work on real systems. Not just Lighthouse scores, but render performance, bundle discipline, data-fetching strategy, and cachingFrontend security awareness beyond auth-token plumbing. You understand the common attack surface and how to avoid expanding itComfort with ambiguity and the judgment to make decisions when requirements aren't fully formedAs a company specializing in both hardware and software, we value close collaboration within our team. Therefore, we are seeking candidates who can join us at our office in Hamburg. Nice to have Experience with realtime, hardware-adjacent, or kiosk/in-store frontendsManufacturing, production, or operational-tooling context3D, WebGL, or product-visualization experience (Three.js, R3F)PWA and/or native (React Native, Capacitor) experienceBackground contributing to design systems or frontend platform work Background We care about what you can do, not where you learned it. Formal CS background, bootcamp, apprenticeship, serious open-source contributions, or a strong portfolio of shipped work, all valid signals.