Luckily, as Cantor showed, you'd only need an single infinite array to store the necessary data.

That’s only true if the list of programming languages is infinite or if the list of features is infinite.

If you want the list to be expandable without ever reindexing AND you want it to still be relatively compact, you can use Rosenberg-Strong which creates a square shells instead of Cantor’s diagonal shell.

https://arxiv.org/abs/1706.04129

Bonus content: Szudzik shows how Rosenberg-Strong lets you create a bijection from positive to binary trees ordered in a way so that larger integers never yield a tree of height N until it’s exhausted all tree instances of height N-1.

So that was the joke, that there are infinitely many languages and features.

It's not necessary though, your first statement is plainly false as written.

I bet your link has some interesting algorithm in it. Luckily for Cantor he died before every having to participate in a software engineering interview.

Technical PhD thesis defense doesn't count as a software engineering interview(s)?

That’s what I figured. I can tell when someone is trying to shoehorn a premise into the joke to make it work.

Think google using c shell's by the sea shore gives cooler results.

Treating the searchable internet as a collective distributed table would provide for a list of all programming language features accessible via internet search.