You are really asking to be bullshited (even if people had a good answer, they won't have an elevator pitch to tell you in an interview). Unless you are looking for people that can make an argument, you are selecting for the wrong trait.

> You are really asking to be bullshited

The question is rhetorical, so what does this matter? It is part of a job interview. It is not a VC pitch. If this confuses a candidate and they answer a question not asked I would not hire them. Interpreting and following instructions are important skills.

> so what does this matter?

You are select for the "can bullshit people on short notice" ability. It is very likely not correlated with other abilities required for the job, thus, if it is not required, you will very likely fail the stronger candidates because of that.

Creativity is directly correlated with problem solving.

And dishonesty correlates with what?

What dishonesty? The entire thing is a rhetorical exercise on the fly.

Communication is also an important skill. Your question poorly communicates whatever information you are trying to glean from the candidate.

> "how would you build it?"

Where is the complexity in the question and how is it poorly communicated?

It first requires answer to the question "build what?" before the candidate can talk about "how". Unless they would build everything using the same tech, which also would be an odd signal. You putting a specific amount of money on it adds additional concerns regarding that.

Do you expect the candidate to talk about some tech stack and/or development process to you? Do you expect the candidate to describe what they'd work on (then why don't you ask that?)? Do you expect the candidate to to treat the question as "if you could work on whatever you liked", or is it "what kind of product would you build", and then talk about the process? Do you expect the candidate to ask for clarification, or is that a bad sign already (since they were to dumb to understand your "simple question")?...

If the candidate is hopelessly stuck in a state of circular analysis paralysis then the quality and thoroughness of their answer would ultimately suffer. It would demonstrate either poor decision making, weak communications skills, or limited comprehensiveness.

There are a lot of candidates who need to have their hands held by a parent authority or are hopelessly incapable of forming original ideas. This is a means of identifying such people so that they can be removed from consideration.

> Do you expect the candidate to ask for clarification, or is that a bad sign already (since they were to dumb to understand your "simple question")?

If I had to answer the question for the candidate, then yes, I would consider that a bad sign. It is a simple hypothetical question demanding a hypothetical response.

as an open-ended question you gain insight from the candidate's response to the scope with which they think about things (and whether that matches up with their experience)... also 100K isn't much so it should force some critical/creative decisions

The key thing missing from the question is what the thing being built is. Any answer to the question of how to build must (to be coherent) address what is being built, and anyone who has a what to build and a how to build it for a revolutionary product that takes only $100,000 in VC capital should be shopping that for financing, not looking for a technical gig working on someone else's (probably not revolutionary, certainly more expensive to build, and even more certainly providing the candidate less equity) thing.

Presuming this is a technical interview and the skills are already identified and qualified the "what it is" isn't particularly important. This isn't hiring for marketing or product management. Make anything up. In this case the production process and software organization strategies are what matter.

Attempting to bullshit past the spirit of the question with deflections and non-answers are easily identifiable failures.

> Presuming this is a technical interview and the skills are already identified and qualified the "what it is" isn't particularly important.

It may not be important to the person asking the question, but it's actually quite central to being able to have a coherent answer.

A better question, if the “what” isn't important, is to identify a concrete thing rather than a “revolutionary idea”; if “what?” isn't important, don't ask a question which fundamentally requires having an answer to “what?”.

> Attempting to bullshit past the spirit of the question

Asking a poorly framed question and blaming the person questioned for bullshitting for not correctly deducing the intended spirit certainly reflects negatively on someone, just not the interviewee.

That doesn't make any sense, the question presumes you've already acquired the funding.

No, the response "why would he work for you" presumes that knowing how to build a product after acquiring VC funding would include the skill set or interest in acquiring the VC funding.

No, it doesn't, since even without that they would be better served by looking for someone with that skill and being the technical side of the founding team.