A few questions I have left unanswered:

- does the deploy commander create the hotfixes or the engineers who authored the commits?

- it seems that the deployment is fully automated, but engineers still have to be available in case of problems, does that impact productivity?

- "Once we are confident that core functionality is unchanged", is there a particular metric to assert that?

- how long does deployment take currently?

- switching directories doesn't seem like a fully atomic operation yet, isn't there a delay from loading the files and wouldn't that generate 502s from the service? Maybe it's better to create new instances with the new files and then change the router to use those (blue-green)?