Some examples include a machine-readable storage medium with instructions executable by a processing resource of a device to process a file according to a pre-defined workflow. The machine-readable storage medium comprises instructions to receive a message to process the file at a workflow queue, to forward the file, by a policy workflow worker, to a first workflow process worker that corresponds to the file, and to perform, at the first workflow process worker, a first workflow process on the message. The machine-readable storage medium further comprises instructions to return, by the first workflow process worker, the processed message to the workflow queue, wherein the processed message includes the file and a first result, to evaluate, by the policy workflow worker, the processed message against the pre-defined workflow and, based on the evaluation, to forward the processed message, by the policy workflow worker, to a second workflow process worker or an output queue.