Abstract: Techniques are disclosed for processing a workflow campaign. In some embodiments, a message processing service receives a first message that corresponds to a user arriving at a first node of the workflow campaign from a first message queue. The message processing service causes one or more actions associated with the first node to be performed with respect to the user. In addition, the message processing service determines that the first user should be progressed from the first node to a second node of the workflow campaign. The message processing service generates a second message that corresponds to the user arriving at the second node and determines a second message queue that is associated with the second node. The message processing service progresses the user from the first node to the second node by transmitting the second message to the second message queue.