[spreaker type=player resource="episode_id=18590644" width="100%" height="80px" theme="light" playlist="false" playlist-continuous="false" autoplay="false" live-autoplay="false" chapters-image="true" episode-image-position="right" hide-logo="false" hide-likes="false" hide-comments="false" hide-sharing="false" hide-download="true"] Geoff Ralston (@gralston) is the founder of Imagine K12, an education-focused vertical within the super successful startup accelerator YCombinator. Collectively, Y Combinator and Imagine K12 have backed over 100 education technology startups.