MVP/Seed stage founders

Where can I find early stage founders looking to find their first employees or hire. Apart from the likes of LinkedIn, Wellfound, Twitter ... etc.

Any closed/invite only slack/discord communities ? Any specific social network app focusing on early stage founders collab ?

I've previously had chances to work with startups and hands down it had turned out for me memorable experiences working for a thriving idea with amazing people moving very fast. Hence asking.