Latest Batch Of Y Combinator Startups: Established Entrepreneurs Solving Real-World Problems

Y Combinator just wrapped up its 17th, bi-annual demo day in Silicon Valley, and there's a noticeable sheen to the type of entrepreneur standing on stage to pump up the room about their products. Many of them have already made millions on other ventures or had established careers, before packing it in to start a company that could change the world.