Senior Fullstack Engineer Agentic Payments NYC MIA

Engineering · New York City, Miami · Hybrid Senior Full-stack Engineer - Agentic Payments (NYC / MIA) About Crossmint Global financial rails are undergoing a once-in-a-generation transformation. Instant settlement. Programmable. Agent-first. Crossmint is the infrastructure helping companies build for that future.We are the leading all-in-one stablecoin and wallet infrastructure platform, enabling fintechs, enterprises, and agentic platforms to integrate stablecoin rails with speed, compliance, and scale. Crossmint provides everything enterprises need to ship smart financial rails, including smart wallets, cross-chain stablecoin orchestration, on/offramps, token checkout, and more, all through a single developer-friendly API.Trusted by more than 40,000 clients including global leaders like MoneyGram, Western Union, and Paga to nation states like the Marshall Islands, Crossmint powers stablecoin flows that move billions from cross-border remittances, global payroll, to the world's first digital UBI program.MiCA-authorized, PSD2-licensed, and SOC2 Type II certified, Crossmint serves 150+ countries globally across 50+ blockchains. Backed by Ribbit Capital, Franklin Templeton, NYCA, First Round, and Lightspeed Faction.We're building the infrastructure for the era of programmable finance. Join us! Location NYC (preferred) or Miami. Hybrid office setting. Type of employment Full-time Salary range Senior level: 200,000 – 230,000 USD Note: Final level and compensation are determined during the interview process based on experience and fit. Seniority 7+ years building production systems, with a strong backend and full-stack track record. About The Role As a Senior Full-stack Engineer on the Agentic Payments Team, you will build and scale the infrastructure that lets AI agents transact safely and autonomously including the agent wallets, delegated authorization, checkout, and card rails that enterprises and developers use to give their agents real spending power. Your work will directly impact how companies let agents hold funds, make purchases, and pay for services strictly within the guardrails their users define. You'll build our offering across stablecoin rails and the major card networks' agentic programs, including Visa Intelligent Commerce, Mastercard Agent Pay, and more. You will ship enterprise-grade, production-ready services that developers integrate in minutes through secure APIs and SDKs. Responsibilities You will: Write high-quality production code that is correct, secure, performant, and maintainable. Build and scale agent wallet infrastructure: provisioning, signing flows, transaction orchestration, and lifecycle management for wallets owned and operated by AI agents. Design and enforce delegated authorization and programmable guardrails for spending limits, merchant allowlists, human-in-the-loop approval thresholds, and auditable transaction logs that let agents act autonomously within defined boundaries. Integrate agentic card rails, including Visa Intelligent Commerce, Mastercard Agent Pay, and emerging agent payment programs covering virtual card issuance, tokenization, and lifecycle. Build agent commerce and checkout experiences, from conversational checkout to programmatic purchasing, exposed through clean APIs and SDKs. Design scalable, secure systems that bridge agents, card networks, and onchain/offchain components while maintaining data integrity and compliance. Contribute to architecture and design documentation to shape the long-term evolution of Crossmint's agentic payments products. Own features end to end from design to production deploy and iteration. Participate in paid on-call rotations once or twice per quarter. Mentor and support teammates and help raise the technical bar across the engineering organization. About You To thrive in this role, you should have: Strong communication skills in written and spoken English. Bachelor's degree in Computer Science or equivalent professional expe...