[threeseed]

I've worked at three banks and it's not about cost. It's because they aren't stupid.

Young developers often think that banks, insurance companies etc. should just rewrite these "legacy" systems because it will bring all of these magical benefits with no risk. Whereas older developers who have worked on (a) mission-critical applications, (b) major re-platforming efforts and (c) projects in a highly regulated industry know the score.

Doing just one is hard. Doing all three at the same time is suicidal. The chance of project success is basically in the single digits. And the risk of failure is billions in lost revenue and your future prospects in the company and within the broader industry ruined.

[ak_111]

Not so sure, experienced tech managers are also very wary of vendor lock-in and tech debt which mainframes give you in spades.

[ohgodplsno]

The vendor lock-in is a feature to them. They're not a tech company. They're banks. They're insurances. Lock-in means they can send a lot of cash to someone and the problem gets fixed, which is the only thing they care about. And in good news, cash is also a thing they have a lot of. The cost of their tech infrastructure is a blip on the radar compared to payroll, to the cost of their physical spaces.

[threeseed]

I assume from this comment that you've never worked in the enterprise.

Because (a) major decisions like choosing a mainframe are not made by tech managers and (b) every company is built around vendor lock-in.

Who do you think companies like Atlassian, Oracle, Salesforce etc sell to ?

[paleotrope]

It's a little off to think that a mainframe was "chosen". Software and the companies that write it and support it "chose" the hardware for you.