I think you are only proving my point here. They have not provided any specific details about any of this, and did not elect to make a prototype implementation

I think you are only proving my point here. They have not provided any specific details about any of this, and did not elect to make a prototype implementation in Java to actually measure the costs and compare to the other solutions. So you’re precisely right that I don’t know why they chose to dismiss Java as a candidate language. That’s my whole point. If they aren’t going to provide evidence or more detailed explanation of why Java wouldn’t solve it well, then it seems very disingenuous that they do throw in a pejorative comment like saying Java adds unqualified operational complexity. And the same thing for unqualified “unsafety” of C or C++. I’m willing to cut them more slack about C/C++, but still there is zero need to toss in these pot shots as if those languages are always inferior in an absolute sense (that is the only thing we can possibly think they mean, literally because they dismiss those choices out of the box with little discussion and no experimentation). They could have just said something like this: “We elected to create candidate implementations in node, go and rust. We did not elect to consider Java, C or C++, but would encourage others to evaluate those alternatives if they seem applicable in other use cases.”