There's no perfect to know if you've found a great Co-Founder, but there are some really obvious ways to tell you're about to recruit a bad one!
Yet picking Co-Founders isn't something many of us will do more than once in our lifetime, so how could we possibly know what to look for? There's no absolute checklist, but there are 3 categories where most Founders don't press hard enough — Selection, Shared Cost, and Commitment.
Technically there's a fourth, which is "personality type," but that's so incredibly hard to determine in the early stages (see: all of dating and marriage) that it's almost not worth mentioning compared to the Big Three. If all of these start to sound way too familiar, it may be worth thinking about an exit strategy.