Oracle Cloud Infrastructure (OCI) Workflow service is a

Serverless computing is a cloud computing execution model in which the cloud provider runs the server, and dynamically manages the allocation of machine resources. Pricing is based on the actual amount of resources consumed by an application, rather than on pre-purchased units of capacity. [Source: Wikipedia]

workflow engine with a graphical flow designer for developers and architects. It accelerates the creation and execution the orchestration of OCI services, such as OCI Functions, AI/ML, to perform enterprise logic, IT tasks, and data jobs.