I think it depends on level you're interviewing at. New college hires rarely have much a clue about this but engineers and senior engineers should be able to have a conversation about it. To be fair because of time constraint, I don't have candidates code this but do want to entertain the discussion. For example, what happens if i pass "illegalValue" to your method, or what do you think your solution should do when the service dependency you call fails to return.

The sentiment is important because it shows how a candidate ties the requirements to the customer use case that it is serving. Not being able to connect these two is a concern in my mind especially for those who are not new college hires with little real world experiemnce.