Product Engineer, San Francisco

funxyz; San Francisco (CA); On-site; USD 120,000 - 180,000; Full time

Job summary

funxyz is seeking a Product Engineer to shape the future of crypto payments. This role focuses on designing and scaling SDKs that power Checkout across web2 and web3, balancing performance, reliability, and user experience.

You will work across protocol, backend, and business teams to tackle complex challenges and build scalable tools for a global audience. Crypto experience is a plus, but fast learners from any technical background are welcome.

Qualifications

• Experience designing and shipping developer-focused SDKs.
• Ability to work across frontend, backend, and platform teams.

Responsibilities

• Design and scale SDK software powering Checkout for web2 and web3.
• Balance performance, reliability, and UX across the stack.
• Collaborate with protocol, backend, and business teams to solve challenges.

Skills

SDK development

Cross-stack collaboration

Web2

Web3

Job description

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.

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.