Its focus is on executing async long-running business logic. Business logic is modeled as workflows and activities. Workflows are the implementation of coordination logic. Its sole purpose is to orchestrate activity executions. Activities are the implementation of a particular task in the business logic. The workflow and activity implementation are hosted and executed in worker processes. These workers long-poll the Cadence server for tasks, execute the tasks by invoking either a workflow or activity implementation, and return the results of the task back to the Cadence server. Furthermore, the workers can be implemented as completely stateless services which in turn allows for unlimited horizontal scaling.