Postgres might have been a perfect answer, but the candidate needs to explain why and how.
The purpose of the interview is for the candidate to demonstrate their thought process and ability to communicate it. “Just use Postgres” doesn’t do that.
This would be more obvious if it was a LeetCode problem and the candidate just regurgitated an algorithm from memory without explaining anything about it. Yeah it’s technically the right answer but the interviewer can’t tell if you actually understand what you’re talking about or if you just happened to memorize and answer that works.
Interviews are about communication and demonstrating thought process.
100% interviews are about communication and demonstrating thought process; after going through some rounds of interviewing candidates myself, any candidate who can adequately explain what they're thinking and how they arrive at their conclusions will be able to demonstrate their skills much more thoroughly than 'just use Postgres'.
That being said, it's also on the ones giving the interviews to push the candidates and ensure that they really are receiving the applicants best. The interviewers don't want to miss potentially great candidates (interviews are hard and nerve-wracking, and engineers aren't known for their social performance), and thus sometimes need to help nudge the candidates in the right direction.
Fully agreed on the point that interviewers should prompt and push candidates in the right direction.
The best thing someone can do to learn how to perform well in interviews is to sit on the other side where you’re interviewing candidates. Some candidates will get stuck on arguing some irrelevant point or trying to fight against the interview question for too long in an interview. Once you see how much it hurts the interview process you learn to never do it yourself.
I went to law school and a few of us students were engineers. For our first set of essay exams, the professors all instructed us to "just answer the legal question" and not include extra analysis. After the exam, many of the engineers didn't do well because the professors *actually* wanted you to weave the whole sylabus into your answer (i.e., discuss hypotheticals that were not actually part of the question asked), not just answer the question. After that, we were fine.
This is also what I learned the hard way. In many situations the customer doesn’t say what they really want. There are a lot of reasons why. I usually have to write down a lot of hypotheticals. If X is the primary concern, we should do Y. If U is the issue, we should do V.
I wouldn't expect customers to say what they really want. They are looking for faster horses after all. But law professors? Among all professors, law professors should be the ones saying what they really want.