As of version 0.1.4, Drake supports optional asynchronous execution of steps in a workflow.

Use the --jobs option to specify how many parallel threads of execution you'd like to allow for a workflow run. When --jobs is set, Drake will run independent steps in parallel, using as many threads of execution as there are steps that can be run asynchronously, up to the maximum amount specified.

For example:

drake --jobs 8 +...

By default, --jobs is set to 1, meaning steps are run strictly serially.

When --jobs is greater than 1, stdin redirection for a step will cause Drake to hang. Therefore you should avoid programming cli interation into any of your steps unless it's absolutely necessary and you know you won't be running async.