After graduating from Middlebury College, Ryan got his start in television when he entered and won the Norman Lear Playwriting award sponsored by Columbia Pictures Television (which later became Sony). The award included a $25,000 cash gift and meetings with Columbia's top television producers. Later he was a staff writer on the show "Nash Bridges" and served as a writer/producer on "Angel" before creating and acting as Head Writer on "The Shield". He was partnered with David Mamet to serve as showrunner for "The Unit".