Yesterday I participated in Code Retreat #2 on the Lean Dog boat, formerly Hornblower's restaurant, a converted barge parked on the shore of Lake Erie a couple of blocks from the Rock and Roll Hall of Fame in Cleveland, Ohio. Facilitated by Patrick Welsh, J.B. Rainsberger, and Corey Haines, the event attracted about 30 software developers who were interested in honing their professional skills by pairing with peers to practice test-driven development and emergent design techniques.