I'd play the other side for a moment. You describe as red flags essentially that there is currently no business side for a project, hypothetical or real. But t

I'd play the other side for a moment. You describe as red flags essentially that there is currently no business side for a project, hypothetical or real. But there are presumably some specifications, some prototypes, development work, tests, bug fixes, demos etc. - the whole system. Surely all those different aspects of the coherent achievement demonstrate the viability of the idea. > And make some friends, ffs. Following Norvig, one ought to spend significant efforts to become good at something. Making friends - especially those who'd be able to share the unusual road of startup founding - isn't something which would be recommended to come lightly or carelessly. If OP formulates the question for the solo founders, it surely would be interesting to hear which variants there are. Should engineers - here, on YC - regret they were focusing on technical sides instead of jack-of-all-trading and constantly searching for potential mates?