Comment by fock

I work at a shop (a specialized provider for finance in your eyes) which still has the "transaction" workload on IBM z/OS (IMS/DB2). The parts we manage (in Openshift) interface with that (as well as other systems) and I have heard of people/seen the commits moving PL/I to Cobol. In 2021. Given Cobol's nature, those apps have more than 1k LoC easily.

We also sublease our mainframes to at least 3 other ventures; one of which is very outspoken they have left the mainframe behind. I guess that's true if you view outsourcing as (literally) leaving it behind with the competitor of your new system... It seems to be the same for most banks, none of which are having mainframes anymore publicly, but for weird reasons they still hire people for it offshore.

Given that our (and IBM's!) services are not cheap I think either a) our customers are horribly dysfunctional in anything but earning money slow and steady (...) and b) they actually might depend on those mainframe jobs. So if you are IBM or a startup adding AI to IBM I guess the numbers might add up to the claims.