If you need to switch back to a previous version of a model, you can do so using the ScienceOps web application. Navigate to the model's version page (i.e.
/models/HelloWorld/versions), find the version you'd like to rollback to, and click the corresponding "Redeploy" button.
A deployment will occur for that version of the model. The current version of the model will remain active until the version being deployed is ready. A zero-downtime switch will be made and the previous version of your model will now be online and ready to receive predictions.