You will drive the technical roadmap, translate business and functional requirements into robust systems, evaluate emerging technologies, and oversee end-to-end delivery-from scoping through production issue resolution-across critical monetization domains, including product catalog, billing, and payments. System Design: Expertise designing fault-tolerant, event-driven architectures where data integrity is paramount-mastery of idempotent APIs, ordered messaging, event sourcing/durable logs, and at-least-once/effectively-once guarantees.