Uh, Java is specifically supported by IBM in the Power and Z ISA, and they have both their own distribution, and guides for writing Java programs for mainframes in particular.

This shouldn't be a surprise, because after Cobol, Java is the most enterprise language that has ever enterprised.

The way Java is practically written, most of the overhead (read: inefficient slowdown) happens on load time, rather than in the middle of execution. The amount of speedup in hardware since the early 2000s has also definitely made programmers less worried about smaller inefficiencies.

Languages like Python or JavaScript have a lot more overhead while they're running, and are less well-suited to running a server that needs to respond quickly, but certainly can do the job well enough, if a bit worse compared to something like Java/C++/Rust. I suspect this is basically what they meant by Java being well-suited.

I am a programmer but I'm not sure why people think Java is suited for anything, especially a system so sensitive to bugs. It's so hard to write high quality readable code in Java. Everything is way more clunky, and verbose than it needs to be.

Some major improvements were made with versions 17+ but still, it feels like walking through mud.

It's a language from the 1990s for the 1990s.

Btw the performance is actually pretty good in Java, the old reputation for slowness is entirely undeserved today.

Other than hardware issues, which someone else mentioned, it has a lot of enterprise-grade functionality that make it more secure and auditable than a lot of other languages. And despite, or maybe because of, its large memory footprint it's actually faster than most languages.

I totally get any hate about writing Java though. It is a verbose language. Using Kotlin instead helps with that.

I was briefly employed at a firm that maintained the sales commission software for a large telecom firm.

It was 1.5 million lines of VB6, though VB8 was already three years old. Nobody knew all of it, so they couldn’t possibly rewrite it to handle all the edge cases and special incentives we kept having to add.

Except maybe the lone QA person, who would frequently begin sobbing at her desk. And we could all hear it because it was an open plan office and we weren’t allowed to wear headphones.

That job was so bad I quit and began freelancing.

Similarly, my company are 4 years into a rewrite of a cobol mainframe system much simpler than Social Security. Which was going to "take a year" there's at least 5 years left.

I know the UK benefits system took well over 12 years to build with an programming workforce of over 2000 and I imagine it's simpler having to support a population one fifth the size of the US.

The kind that thinks full self driving is two years away, perhaps?

He can't be this delusional, right? It is almost like he is just trying to inflict damage?

The kind that thinks all those edge cases don't matter and if they don't get payments it's just another example of "waste, fraud, and abuse."

And I think "vibe" means that they have no experience with programming so they can't read the code they copy.