Back End Engineer - Fun.xyz

At Fun.xyz, we believe a tokenized future is a beneficial inevitability, granting financial emancipation to everyone with an internet connection. For a blockchain-first global economy to exist, value exchange must become intuitive, secure, and seamless.

Enter Checkout - the highest converting payment solution in web3. By integrating Checkout, dApps enable users to complete any on-chain action using crypto from a wallet, centralized exchange, or on-ramped fiat from a card or bank account. With access to market-leading routing and their asset portfolio at the point of sale, users are faster, stickier, and more engaged. For dApps, Checkout scales their user acquisition potential without launching new chains or integrating multiple third party providers.

We built Checkout because we envision a world where anyone, anywhere, can purchase anything with any asset. If that sounds like a vision you can get behind, we want to hear from you.

About the Role

We’re looking for a BackEnd Engineer to join our growing team at Fun.xyz and help architect the backend services that power our web3 payments infrastructure. This role is foundational to the success of our platform and will shape how payments, settlement, and transaction routing are handled across chains and payment providers. You’ll be working on high-performance, low-latency systems that support complex use cases like asset conversion, identity and security verification, transaction finality, and decentralized routing—while ensuring fault tolerance, scalability, and compliance across a global user base.

Location: Midtown, New York, NY and Singapore (In-office Mon–Thurs, Remote Fridays) Team: Payments Infrastructure – Mid, Senior, Staff, or Principal Levels

Responsibilities

• Design, build, and maintain high-performance APIs and backend services that power our Web3 payments platform

• Build new features to further our product experience

• Collaborate with product and protocol teams to architect technical solutions that meet business requirements

• Write clean, well-tested code and participate in code reviews to maintain high engineering standards

• Contribute to incident response and debugging production issues to ensure system reliability

Requirements

• Strong experience building production backend systems with modern languages

• Proficiency in Typescript

• Deep understanding of distributed systems, APIs, and database design principles

• Hands-on experience with cloud platforms and containerization technologies

• Solid grasp of computer science fundamentals including data structures and algorithms

• Strong problem-solving skills with ability to debug complex technical issues

• Clear communicator who can collaborate effectively with cross-functional teams

Nice to Have (But Not Required)

• Production TypeScript experience

• Previously worked at crypto startup or Web3 infrastructure company

• Experience with blockchain integrations, smart contracts, or DeFi protocols

• Background with high-scale payment processing or financial compliance systems

• Contributions to open source projects or technical writing

• Experience with event-driven architectures and real-time data processing