Product Engineer, San Francisco

Capital markets are undergoing a fundamental shift. Assets that live in fragmented systems and manual workflows are moving onto blockchains -systems designed to move and store value more transparently and efficiently.

While this unlocks more open and programmable financial systems, it also introduces significant complexity. For most users, interacting with this new infrastructure is still too difficult.

Fun builds the infrastructure that powers consumer-facing fintech applications - handling onboarding, account access, and money movement so users can interact with blockchain-based systems as seamlessly as they do with traditional finance.

For fintech builders, Fun provides a best-in-class onboarding and deposit stack that drives conversion and unlocks user growth. We operate at the intersection of financial infrastructure, complex engineering, and product experience.

About the Role

We're looking for a talented Product Engineer (Mid, Senior, Staff) to join our team and help shape the future of crypto payments. In this role, you'll design and scale SDK software that powers Checkout across web2 and web3 environments, working across the stack on systems that balance performance, reliability, and UX. You'll collaborate closely with protocol, backend, and business teams to solve complex challenges and build tools that scale globally to meet the evolving demands of on-chain payments. Crypto experience is a plus, but fast learners from any technical background are welcome.

Requirements • 3+ years of engineering experience with JavaScript, TypeScript, and modern frameworks

• Strong understanding of full-stack development, including React and backend APIs

• Attention to detail in both product design and user interaction

• Proven track record building scalable, high-performance software

Nice to Have • Familiarity with blockchain technologies and EVM-compatible networks

• Comfortable solving difficult technical problems in agile environments

• Experience working on payments, SDKs, or crypto-related systems

• Passion for building secure, efficient, and accessible tools

What Sets You Apart • You've contributed to open-source projects or built SDKs/dev tools

• You have shipped products from 0 to 1 in a fast-paced setting

• You thrive in ownership-heavy environments and pride yourself on execution

• You approach problem-solving with thoughtfulness, precision, and rigor

Why Join Us ● Shape the future of payments and programmable money ● Work with bleeding-edge tech in a domain where innovation moves fast ● Join a mission-driven team focused on access, openness, and trust ● Be a key contributor, not just a cog—your work will ship fast and matter ● Collaborate with top-tier protocols, builders, and financial infrastructure providers

Location and Work Environment This role is primarily in-person at our Midtown, NYC headquarters. We work together Monday through Thursday for fast, iterative collaboration and optional WFH Fridays to reset and recharge.