Well it's kind of hard to just give you a simple answer to your questions Anon, not really knowing anything about your experience or abilities. I don't really frequent these kinds of things myself today, I focus more on learning from highly-experienced developers in the areas I'm interested in. However, I don't think that's exactly the same as what I think I hear you asking.
I personally subscribe to the Go big, or go home
philosophy of life. So I tackle something that so obviously out of my depth that it will be a literal miracle by God's grace when we actually pull it off. That's how I 'challenge' myself in this kind of thing. I think you'll probably need to figure out your own way towards that in your own life Anon.
Good luck with it.