How to Find a Position as CTO/technical co-founder?

Posting so I can give share feedback with my dad. He is a software engineer by trade, and in 2021 sold an engineering consulting firm for low eight figures (he was one of several shareholders). He now has a cushy corporate job that he is hesitant to leave, but he’s expressed interest in starting another company, or joining an early startup as a technical cofounder/CTO. He is not a businessman by trade, although he can help in this area but he excels in software engineering/consulting/design. He says he’d love to start a new company but knows to succeed he needs a killer idea. I frequent this sub just out of curiosity but I’ve heard of some sort of platform where founders network. Where can my Dad look for people seeking a CTO/technical founder? Is there one specific platform or many? Thanks! TL:DR: Where can a software geek find startups offering equity looking for developers or technical co-founders?