Just some fundamentals I can think of off the top of my head. I'm surprised people saying that the lower level systems/hardware stuff are untransferable. These things are used everywhere. If anything, it's the AI itself that's potentially a bubble, but the fundamental need for understanding performance of systems & design is always there.
Re Oracle and "big 90s names" specifically, there is a lot of it out there. Maybe it never shows up in the code interfaces HNers have to exercise in their day jobs, but the tech, for better or worse, is massively prevalent in the everyday world of transit systems and payroll and payment...ie all the unsexy parts of modern life.
And wait until I tell you about my Cobol open seats - on modern Linux on cloud VMs too! :-)
