Senior Engineer (Fintech/Payments) - Rewards Platform, Contract-to-Bigger

We're a funded NYC fintech startup (pre-seed led by a top-tier Silicon Valley fund) building a rewards-redemption platform that connects banks and card programs to live event and travel experiences. We're integrating with major financial institutions and payment networks now. The work: Own delivery of our MVP against a written PRD: inventory ingestion from supply partners, redemption processing, and fulfillment — production-ready Design and build bank-facing API integrations (rewards platforms, gift-card processors, card networks) Make pragmatic architecture calls for a pre-seed company: ship what proves traction now, defer bank-scale infra until it's needed Work directly with the founder/CEO; communicate timelines in writing and hit them You: 8+ years, with senior/staff/lead experience at a fintech, payments, or marketplace company (Brex/Stripe/Ramp/Plaid-caliber a plus) Have personally shipped production systems handling payments or financial data (tell us which, and your role) Strong across backend + cloud (AWS/GCP), API design, and third-party integration work; comfortable using AI tooling to move fast Startup metabolism: you scope, commit to dates, and deliver without a team around you Engagement: Start ~20 hrs/week contract, structured around 2–3 paid milestones with defined acceptance criteria. Strong performers have a path to a founding-team role with equity. NYC or US-overlap remote (ET timezone required). To apply: In 3–5 sentences, describe the most complex system you shipped end-to-end, your specific role, and how long it took from kickoff to production. Applications without this won't be reviewed.