Lead design and delivery of a partner-facing API and integration program: define API architecture, own product roadmap, write technical specs, create sandbox and docs, support technical sales, build repeatable onboarding playbooks, and code prototypes as needed. Operate within regulated fintech constraints (sponsor bank, KYC/AML, card network rules) and collaborate closely with engineering, data, product, and partnerships to drive partner integrations from 0-to-1.