Rubicon Project is an online advertising technology firm based in Los Angeles, California. It helps clients optimize advertising revenue for web sites. The company was founded in 2007 by Frank Addante, Craig Roah, Duc Chau and Julie Mattern, who had previously worked together at L90, an online advertising network. By April 2009, the company had raised $33 million in venture funding led by Clearstone Venture Partners, IDG Ventures Asia and Mayfield Fund. The company also secured $8 million in venture debt from Silicon Valley Bank.