I need to trigger a job, a command line job, everytime a document is
published with a new version.

Is there any possible ways of doing this?

I had an idea that the user (i.e a service account) that should run the
job, should subscribe to the document. But how do you get the user to
automatically start the job?

Now, the job is scheduled to run once a day, but I only want the job to
run when the document in SharePoint is published with a new version.