How do you find software jobs in startups?

After a few years of experience both in Amazon and Google, I'm looking to work in a startup as a lead engineer / software manager-ish position. Where do I go to find startups that resonate with my values? I'm into energy, health, construction that kinda thing. I don't (yet) care about innovations in crypto or fintech. Oh and I'm based in the UK. #jobhunt #tech #startup