> most engineers contemplate ideas, change their mind, ask clarifying questions
I don't disagree at all. I find it slightly funny that in my experience interviewing for FAANG and YC startups, the signs you mentioned would be seen as "red flags". And that's not just my assumption, when I asked for feedback on the interview, I have multiple times received feedback along the lines of "candidate showed hesitation and indecision with their choice of solution".