Yet now the candidate has no luxury of that, and has to guess the assumptions required to not just produce all the features, but also the quality metrics the project will be measured against. All in the deadline given by you. And he is at day 1, and that's all the day they have.
This is really like expecting some one to fix a problem in a day, what the other person spent months solving.
What ensues is actually comical. During "grooming" sessions the "programmers" are meant to give accurate estimates of how long (I know time is not meant to be the metric but it always is) a story will take to complete. A story which there are many, many person hours of context baked in that the "programmer" is seeing for the first time.
Context is worth 80 IQ points --- Alan Kay.
It would have been a lot cheaper not to have the take home project, but we decided it was worthwhile anyway.
(Disclosure: our project looked a lot like a story you'd be asked to work on in your first week with us. There was none of that "hiring for a Python backend engineer; here's a Scala data engineering project" nonsense.)