> Markdown version of [/jobs/ext/3959253-senior-frontend-engineer](https://www.wearedevelopers.com/jobs/ext/3959253-senior-frontend-engineer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Frontend Engineer - **Company:** The Holladay Corporation - **Location:** New York, NY, United States - **Experience:** Expert - **Salary:** $150,000.0 - $250,000.0 - **Contract:** Permanent contract - **Skills:** Clean Code Principles, Application Programming Interfaces (APIs), Software Quality, Programming Tools, Payment Systems, Design of User Interfaces, Human-Computer Interaction, Open Source Technology, Performance Tuning, Blockchain, Responsive Web Design, TypeScript, Web Standards, ReactJS, Pixel Perfect, Backend, Web3.js, Bitcoin, Front End Software Development - **Published:** October 27, 2026 - **Apply:** https://www.careerbuilder.com/job-details/senior-frontend-engineer-san-francisco-ca--87c0873b-2cc0-48d1-bcbb-633dde0399d7 ## About the Role User Interface/Experience (UI/UX), Embedded Systems, Ecosystems, Customer Conversion, User Interface/Experience (UI/UX), Customer Relations, Cryptography, Customer Experience, Blockchain, Leading Edge Technology, Frontend Expertise: 5+ 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. ## Description 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.