Ask HN: The Signal and the Noise in the Startup World

It is a common thing that good technical people get a large number of opportunities to join new startups, either as a co-founder or as a first employee, and the majority of these startups fail for various reasons. I'm curious how do people evaluate such an opportunity? Especially in startups, as there are no patterns for success. And it can easily ruin the work-life balance in its early days, so the cost of committing to one is very high.

TL;DR, what criteria(s) do you consider when joining a startup as a co-founder or as the first employee?