Trust your instincts about people
Paul Graham is a bit of a weird dude, especially in recent years, especially on Twitter X, but I do believe he has some good, hard earned wisdom on building products and working with people.
This particular quote I’ve found to be exceptionally true in my professional and personal life:
You can, however, trust your instincts about people. And in fact one of the most common mistakes young founders make is not to do that enough. They get involved with people who seem impressive, but about whom they feel some misgivings personally. Later when things blow up they say "I knew there was something off about him, but I ignored it because he seemed so impressive."
If you're thinking about getting involved with someone — as a cofounder, an employee, an investor, or an acquirer — and you have misgivings about them, trust your gut. If someone seems slippery, or bogus, or a jerk, don't ignore it.
This is one case where it pays to be self-indulgent. Work with people you genuinely like, and you've known long enough to be sure.
Paul Graham