A company uses a cloud-based HR system as its authoritative source for employee data and subscribes to a dozen SaaS applications through an Identity-as-a-Service (IDaaS) provider. Currently, help desk staff manually create and disable accounts in each SaaS app whenever HR records change, causing delays and occasional missed deprovisioning. The security architect wants a standards-based way for the IDaaS platform to automatically create, update, and disable user accounts in the downstream SaaS applications based on the HR system's data. Which technology best meets this requirement?