Because converting more than 1 letter to upper case is more computationally expensive than converting 1 letter to upper case.

Not sure what you're trying to say. But this solution is wasteful.

Is that supposed to be an excuse?

There's no type coercion in string > string.

They didn't exist back when I submitted this senior-level code.

Most of it is a Brainfuck interpreter. The ASCII art contains a Brainfuck program that creates the string "hello world!". All the non-instructions ("@" e.g.) are ignored.

What concatenation? This solution uses basic arithmetic. Simple and performant.

Yes, this is my code. You should see my name above it.
What's hard about this solution?
Have you read Clean Code?
Btw., with 10+ years of experience you usually don't need to write code in interviews, at least were I live.

Not sure if trolling.

99/10 results in 9, not 9.9. Integer division.

“Way too much code.” Is this a joke?
Delete the first function and the code won't compile. So much for “completely pointless.”

The test cases should contain a name with a space.

This solution is deprecated!

New best practices :kappa:

Not sure. Show your whole code.