[niwtsol]

It is so wild to me the idea of large enterprises that rely on the big "old" databases (db2, IMS, vsam) - on one hand, I think "there must be a whole devops crew that supports these on-prem systems that are super old and unique" and the other hand is "they must be pretty reliable for the task at hand and no one wants to touch the migration project to update." Which makes me think these are still in use at the biggest and oldest enterprises( banks, government entities). Would love to hear any anecdotes from folks who work on those today.

[zenethian]

A DevOps crew? Mainframes aren’t something that are just part of some random web app project in a company. A System Administration team would be the likely maintainer. But a lot of mainframes are designed to be run with very little manual maintenance these days.

They’re also wildly different architecturally from your typical rack of x86 servers, which is why the initial reaction to Linux running on a mainframe sounded stupid at first. When I worked at IBM in the 2010s, a Linux Zserver felt more like a VM running inside the mainframe than anything else. There were abstractions of the mainframe components that intentionally leaked into the Linux side that were interesting. I knew very little about traditional mainframe software development at the time, so I was very fascinated by how it all worked.

[nicholasbraker]

I don't have firsthand experience but I do know that IBM mainframes (Z-series) are still actively developed and lifecycled. Whether this is purely financial (as in: we keep the customer locked in to our ecosystem regardless if there are alternatives available which offer the same level of robustness etc.) or the platform really is better suited to the specific requirements set by banks, government agencies etc. remains to be seen..