Yang founded Yahoo! in 1994, served as CEO from 2007 to 2009. He left Yahoo! in 2012. He founded a venture capital firm called AME Cloud Ventures and, as of 2015, serves on several corporate boards. According to Rob Solomon, a venture capitalist at Accel Partners, Yang was "a great founder, evangelist, strategist and mentor," having "created the blueprint for what is possible on the Internet."
While studying at Stanford in 1994, Yang and David Filo co-created an Internet website called "Jerry and David's Guide to the World Wide Web," which consisted of a directory of other websites. As it grew in popularity they renamed it "Yahoo! Inc." Yahoo! received around 100,000 unique visitors by the fall of 1994. In April 1995, Yahoo! received a $2 million investment from Sequoia Capital, Tim Koogle was hired as CEO, and Yang and Filo were each appointed "Chief Yahoo." Yahoo! received a second round of funding in the Fall of 1995 from Reuters and Softbank. It went public in April 1996 with 49 employees. In 1999, Yang was named to the MIT Technology Review TR100 as one of the top 100 innovators in the world under the age of 35. Terry Semel, who replaced Tim Koogle as CEO after the dot-com bubble crash, served until 2007 when the rise of Google led the board to fire him and appoint Yang as interim CEO.