BuildUp Marketplace Level 0 Context DFD maps a construction marketplace connecting four external entities—homeowners, material vendors, service providers, and system administrators—through a central BuildUp Web System. Data flows bidirectionally between each stakeholder and the platform, enabling requests, service delivery, inventory management, and moderation. This context diagram establishes system boundaries and actor interactions essential for requirements gathering and downstream detailed DFD decomposition. Fork this diagram on Diagrams.so to customize stakeholder roles, add new external entities, or refine data flow labels for your marketplace design.