Sam Chaudhary - https://twitter.com/samchaudhary_ - is the cofounder and CEO of ClassDojo - https://www.classdojo.com/. They've raised $30M and have 30 employees. Karen Lien - https://twitter.com/karenlien03 - is an Edtech Principal here at YC. The YC podcast is hosted by Craig Cannon - https://twitter.com/craigcannon