Our interviews have consisted of something similar, but never in a way that produces actual usable work. We've had candidates "add features" to code, except the code in question was in a language they don't know. So they didn't write anything. We have them tackle past PRs for bugs that have already been fixed. And we've had them do design work for systems/processes we've already built.

We're not evaluating them on whether they got the same answer as us. We care about hearing aloud their thought processes.