Glenn grew up in Bellevue, WA, in a middle-class family.  He was the son of an aeronautical engineer and had two brothers, one of which was a twin brother.  From a young age, Glenn felt like he didn't fit in with other kids at school because most of them were rich kids that showed off their wealth.  His older brother frequently made front-page news in Bellevue, which added to his feeling of difference growing up.

He would then attend the University of California-Berkeley and get his B.A. in English.  He made an attempt to write a novel, and after running out of money and hitting a low point in his life, he decided writing a novel wasn't meant for him.  He would then go on to meet some brilliant people whom he started a business with (Plumtree Software).  That business would eventually be purchased by a large company (BEA) in 2005 after going public and raising $40 million.

Shortly after, he joined Redfin as their CEO and has been there ever since.  Redfin is a publicly traded, technology-powered real-estate brokerage now valued at over $1.7 billion, and is revolutionizing the way people are buying and selling homes.