Matt Hackett and Casey Neistat are the cofounders of Beme, which was acquired by CNN last year – https://beme.com/
You might already know Casey from his YouTube channel which now has over 8M subscribers – https://www.youtube.com/user/caseyneistat
And before Beme, Matt was a Hacker-in-Residence at betaworks and the VP of Engineering at Tumblr – https://twitter.com/mhkt
YC’s podcast is hosted by Craig Cannon – http://twitter.com/craigcannon