We're also approving developers with notable GitHub accounts, Computer Science grads from top Universities, etc. but it's not perfect.
Employer & education are only a rudimentary filter for the time being - some of the best engineers I know are self-taught and work at companies you might not have heard of. It's a big challenge, and we'll get there eventually.
I'd love to get your ideas on how to filter through candidates and then communicate their value to prospective employers in a credible way.