Multi-phase e-commerce sequence diagram modeling an online art marketplace with customer and artist workflows. Nine distinct phases orchestrate interactions from registration through Auth Service, artwork uploads via Art Inventory and Discovery, cart management, checkout with Order State Mgmt, invoice generation, and admin monitoring—all persisting to a Central Database. Demonstrates event-driven microservices architecture for dual-sided marketplace platforms where sellers (artists) and buyers (customers) interact through specialized services. Fork this diagram on Diagrams.so to customize service boundaries, add payment gateway integrations, or model your own marketplace transaction flows. Ideal reference for teams building GCP-hosted platforms requiring complex state management across user roles.