How do you quickly figure out if a potential co-founder is the right fit?

I've been on a hunt for a co-founder, and the hustle has been real. I was advised to get one I've had a relationship with but I have none, so I'm kinda meeting up with new people from different pools, including friends, and mutual connections.

I’ve had deep discussions about values, work styles, problem-solving approaches, and handling tough situations. But let’s be honest, talking about it is one thing, and real-life execution is another.

I don’t have months to wait and see if they're a good fit, so I’m looking for practical ways to gauge who’s the best long-term fit.

Has anyone on here found a co-founder quickly before? What’s worked for you?