Assuming that your company has a profitable business, and you are working on the part brings in the revenue that pays the bills, you'll keep that as long as your company is interested in keeping that business. Your CTO is burning money (and fast!), maybe they've picked that habit up in a zero-interest environment, but well interest rates aren't zero anymore, so I'd be more worried if I were part of the secret internal startup.
Java is not very much older than Javascript and at the time it was far from the world's first programming language. It probably was measured by hype in developer circles the Rust of the mid-nineties.
Not sure if it counts as not widely used, but I think the Collections.unmodifiable(Collection|Set|List...) methods are very useful.
Seconded. Really, anything but the oracle JDK.
Well, it makes the client-side calls a bit simpler if you don't distinguish create and update via POST/PUT, so at the server-side you have a single POST endpoint which does the upsert, but there it would be sensible to dispatch to separate methods for insert and update each.
Why is that?
Programmers are humans and that's the way humans behave. You'll find plenty of ego everywhere, you just selected yourself into our profession and probably don't meet too many people on a different professional path.
Well, if you factor in tuition fees, cost of living and opportunity costs (reduced income because you'll likely wont work fulltime anymore), do you expect to get a job afterwards - that you could not get with your current qualifications - that will pay off those costs? You've got a degree in mathematics, so you'll do the calculation...
Do you know that scene from Good Will Hunting where Ben Afflecks' character says to the snobby student who tries to waive with the prestige of his school: "you dropped 150 grand on a fuckin' education you could have got for a dollar fifty in late charges at the public library"?
If you want to grow your skills you can do it three orders of magnitude cheaper than with a degree program by studying from books or taking dedicated courses and seminars. Consider if you want to go down a path where the credentials are really a requirement or just a nice entry in your resume.