It’s often not as easy as deploy -> immediate problem -> rollback. Problems can take a while to diagnose, or may cause some kind of poisoning that needs to be fixed (eg rebuild a lost or corrupt cache), or be in some part of the system that nobody knew was related (eg maybe someone deployed code that talks to a hitherto-unqueried accounting system and that worked fine at 4pm on Thursday but come 9am Monday it melts).
My point is that in big complex systems sometimes there is not a straight line between cause end effect. Sometimes there’s just effect and you need to work out the cause.
My point is that in big complex systems sometimes there is not a straight line between cause end effect. Sometimes there’s just effect and you need to work out the cause.