This article brings up some very simple software engineering problems and the most obvious/widely used approach to dealing with them, but this is by no means th

This article brings up some very simple software engineering problems and the most obvious/widely used approach to dealing with them, but this is by no means the only approach that works best at scale. Also not necessarily the best approach at scale because sometimes you do need to roll back. If you're serious about writing robust and reliable systems, think about V-1 and V+1 not just the version you are writing and deploying. The point about your code interacting with multiple versions in production is a good one, but also upgrades and downgrades should be considered.