We would like to deploy multiple versions of the same code.

Concretely, we have a background worker that we would like to keep running until all its jobs are finished. Only then would we want to spin it down. But, simultaneously, we would like to spin up a new version of the background worker if there is a code change.

Therefore we would like to be able to run Worker 1.0, Worker 1.1, Worker 1.2, etc. simultaneously.