I dont have to ask anything, the interview process normally speaks for itself. If they have the emotional intelligence to have a mature discussion about their company, product, and after questions to you, they sell themselves as a potential employer, it's a good sign. If it's mostly inane gotcha questions followed by an email to do 3 hours of leetcode monkey tricks, I've seen all I need to see about the how they view the quality of leadership.

What do you mean by competent, and what are you looking to get out of the job?

Once you define those, you should be better positioned to determine if the company and the founder are a good fit for you.

by competent i mean, enough to fundraise and build a team. i think the thing im most looking to get out of it is experience building a team from scratch around me while also creating a tech culture, but none of that can happen without the founder first raising money.

The easiest way to tell if a founder will be able to raise money is to see if he's done it before successfully. If he hasn't, I wouldn't count on it happening in the near term.

I'd be very wary of joining a startup that needs to raise money (i.e. can't bootstrap itself to profitability/exit for some reason) before it has raised money without a substantial equity position and a clear leadership position.

It sounds to me like this company is early enough that it's going to be very hard to evaluate the likelihood of success, so you want to make sure you're prepared for the personal financial risk that entails and that you're compensated for it in some form.

It also sounds to me like you're putting a lot of faith in the CEO to make the company a success and bring you along for the ride, while in reality a lot of responsibility will lie on your shoulders as a very early employee.

Having a conversation with the CEO about these issues should help you decide whether this startup is a good fit for you, but I still think you need to determine if the position is a good fit for you personally.