Senior Frontend Engineer

ABOUT HALLIDAY Halliday is a blockchain company and product lab working to create a unified, cross-chain payments ecosystem. Its flagship product, Halliday Payments, is a unified payments platform that makes it easy for users to onramp, swap, and take other onchain actions. Halliday’s products are built on the Workflow Protocol, which removes the need to code smart contracts by hand and enables breakthrough applications to ship in hours, not years. Backed by a16z and #Hashed, Halliday has worked with prominent developers such as ApeChain, Story Protocol and DeFi Kingdoms to provide seamless experiences for both developers and users. The team includes alumni from Stanford, Harvard, Compound, Meta, Netflix, and more. ABOUT THE ROLE We're looking for a senior-level frontend engineer with deep React and TypeScript experience to build consumer-facing crypto and payments products. As a Frontend Engineer at Halliday, you'll build the user-facing products that power the future of blockchain payments. You'll design and implement intuitive, high-performance interfaces that make onchain transactions seamless for millions of users. This is an opportunity to work on cutting-edge technology with a talented team that's redefining how people interact with blockchain. WHAT YOU'LL BE DOING Build User-Facing Products: Design and develop responsive, performant frontend applications using React and TypeScript that interact with blockchain networks, payment systems, and DeFi protocols while delivering an exceptional user experience. Develop Core Infrastructure: Build scalable components, design systems, and testing frameworks that support our payments platform and developer tools. Ship Developer Tools: Contribute to Halliday's public SDKs and APIs, making it easy for developers to integrate blockchain payments into their applications. Work Cross-Functionally: Collaborate with product, design, engineering, and partnerships teams to deliver features that solve real user problems and drive product adoption. Drive Technical Excellence: Identify and implement improvements to enhance performance, accessibility, security, and code quality across our frontend stack. Innovate on Web3 UX: Push the boundaries of what's possible in blockchain user experiences, making complex onchain actions feel simple and intuitive. WHAT WE’RE LOOKING FOR Frontend Expertise: 2+ years of experience building production frontend applications with React and TypeScript. You write clean, maintainable code and care deeply about user experience. Technical Proficiency: Strong understanding of modern frontend development including state management, API integration, responsive design, and performance optimization. Product Mindset: You think beyond just implementing features, you understand the "why" behind what you're building and advocate for the best user experience. Fast Learner: You're excited to dive into new technologies, whether that's blockchain SDKs, payment APIs, or emerging web standards. Collaborative Spirit: You work well with cross-functional teams, communicate effectively, and thrive in a fast-paced startup environment. Location: Based in or willing to relocate to the San Francisco Bay Area or New York City. NICE TO HAVES Blockchain Experience: Previous work with blockchain technologies such as EVM-based chains, Solana, or Bitcoin. Familiarity with Web3 libraries like ethers.js, viem, or wagmi. Payments Background: Experience building payment flows, checkout experiences, or financial products. Full-Stack Capabilities: Comfort working across the stack when needed, including APIs and backend services. Design Sensibility: Strong eye for design and experience working closely with designers to implement pixel-perfect interfaces. Open Source Contributions: Active participation in open source projects or maintenance of public libraries. WHY WORK AT HALLIDAY? A role with significant autonomy to build out the next generation infrastructure of the blockchain space. Competitive comp