[KaiserPro]

> Cloud is the answer when our systems couldn't horizontally scale fast and reliably enough.

Not quite, the cloud forced you to figure out how to scale, do reliability and all the hard parts, mainly because AWS didn't offer any features like zero downtime VM transfers or any kind of pracitcal storage migration.

The point of the mainframe is that its almost like a really fucking huge lambda function host. You sling your app on the mainframe, ask for resources and let it run. If you run out of capacity, buy another mainframe and link it to the old one. Need a new region/reliability zone? pay a license, install a fat network link and jobs a goodun.

There are videos of where HP/IBM literally blows up a mainframe to prove its auto failover skills.

THe cloud is a poor proxy of what a mainframe _could_ do at its best. But its a reasonable facsimile of what a main frame did at it's worst.

[candiddevmike]

And this tight coupling of code/process/data/apps to the platform is why mainframe migrations have a strong tendency to crash and burn. Folks should look at mainframes as a cautionary tale of "platforms".