Senior Product Engineer, Frontend

We're looking for a Senior Product Engineer, Frontend to join the team building Zerion Wallet. In this role, you'll own product experiences end-to-end — from understanding the problem and shaping the interaction to implementation, launch, and iteration. We're looking for someone who combines strong frontend engineering skills with product judgment and an unusually high bar for design and craft. We care not only about whether something works, but how it feels to use — and you should be comfortable challenging a solution when the experience isn't good enough. We value strong ownership, attention to detail, and the ability to move fast without compromising product quality. What You’ll Do • Own complex product features end-to-end — from understanding the problem and shaping the solution through implementation, launch, and iteration. • Work closely with the product team to shape what we build, challenge assumptions, and turn ambiguous problems into great product experiences. • Build polished, responsive product experiences using React and TypeScript. • Prototype and iterate on interactions quickly, using code, design tools, and AI to find the right solution. • Obsess over the details that make interfaces feel great: interaction, motion, responsiveness, loading states, transitions, and microinteractions. • Build and evolve reusable frontend components and our design system, improving consistency without sacrificing flexibility. • Proactively identify places where the existing product experience can be improved — and take ownership of improving them. • Maintain a high bar for performance, accessibility, reliability, and frontend engineering quality. What We’re Looking For • 5+ years of experience building high-quality, customer-facing web products. • Excellent knowledge of React, TypeScript, modern CSS, and browser technologies. • A track record of owning and shipping complex product features end-to-end, rather than working only on isolated components or implementation tasks. • Strong product and UX judgment — you can recognize when an interaction doesn't feel right and propose a better solution. • Exceptional attention to detail and a desire to build interfaces that feel polished, responsive, and intentional. • Experience building sophisticated animations and interactive UI. • Strong understanding of modern frontend engineering practices and the judgment to know when and how to apply them. • Comfortable taking an ambiguous product problem and turning it into a concrete solution. • Strong ownership mindset — you take responsibility for outcomes, not just tasks. • Strong desire to actively contribute to product evolution, not just implementation. • Comfortable operating in a fast-paced startup environment and working on multiple problems in parallel. • Clear and proactive communication in a distributed team. Technical Skill Set • Excellent knowledge of React and TypeScript. • Strong command of HTML, CSS, browser APIs, and modern frontend architecture. • Experience building responsive, high-performance web applications. • Experience with animation and interaction libraries and building complex UI transitions. • Experience building reusable component systems and frontend abstractions. • Strong understanding of frontend performance, accessibility, and cross-browser behavior. • AI-native workflow is your default for product exploration, implementation, debugging, and iteration. Bonus Points • Experience building or evolving design systems and component libraries. • Strong Figma skills and the ability to explore interaction ideas independently before implementation. • Experience building highly interactive consumer applications where performance and perceived performance matter. • Experience with Browser Extension development. • Hands-on Web3 experience: wallets, dApps, blockchain interactions, or DeFi. • Prior experience in a startup environment that emphasizes trust and autonomy. • Located in time zones close to Europe for smoother collaboration. • Curiosity and willingness to challenge existing solutions when better ones exist. Why You Should Join   Company Overview   Zerion API Trusted by 50+ top crypto and fintech brands Powering 2k+ active clients monthly Over 10B total requests processed A lean, senior AI-native team shipping at outsized scale   Zerion Wallet 1.7M+ active funded wallets 27.6M+ transactions 2.5B+ transaction volume 416K+ unique holders of Zerion DNA NFT     Culture: Our culture shines through in our strong team engagement and impressive retention, showing just how much we value creating a workplace where people truly want to stay and thrive. People: Collaborate with some of the most driven and intelligent individuals in the crypto space. Salary & Benefits: Receive a competitive salary, medical insurance, coworking membership, and additional benefits. Unlimited Days Off and Flexible Work Schedule: Recharge and explore life outside the office with our flexible time-off policy and work schedule. Remote Work Essentials: We provide all the necessary software and equipment to ensure you're fully equipped to work from home comfortably and efficiently. Stock Options: Contribute to Zerion's success and watch your stock options become valuable. Travel: Connect with your teammates around the world at industry events and our annual team offsite. Distributed Team: Zerion is a fully remote team with members worldwide. Embrace asynchronous collaboration, find your own work rhythm, and enjoy a healthy work-life balance.   To ALL recruitment agencies and individual recruiters: Zerion only accepts resumes from its partners, with whom Zerion has contractual relations. Zerion is not responsible for any fees or charges associated with unsolicited resumes.   We read every application in full before moving forward - as part of that, please include the word WATERMELON somewhere in your answer to the application question below