Byrnes has been with the Dodgers since November of 2014. Prior to that, he worked in the Cleveland front office in the 90s when John Hart was there before joining the Rockies in 1999 as assistant general manager under then-g.m. Dan O’Dowd. Fun Rangers-related note — Byrnes is who interviewed and hired Jon Daniels for JD’s first job in MLB while with the Rockies.
Byrnes subsequently joined the Boston Red Sox in 2003 as assistant general manager under g.m. Theo Epstein. The Arizona Diamondbacks hired him as their g.m. after the 2006 season. He was fired by the D-Backs, along with his controversial managerial hire, A.J. Hinch, on July 1, 2010. He joined the San Diego Padres front office after that, ultimately taking over as general manager in 2011. He was fired in 2014, and was replaced by A.J. Preller.
Byrnes has, per the Dodgers’ website, “supervise[d] the club’s scouting and player development.” Given how well the Dodgers have scouted and developed players over the past decade, and given how the Rockies’ first priority is improving that area of their organization, one can see how Byrnes would be a good fit for the Rockies. In addition, Byrnes has worked continuously in MLB for over 30 years, while DePodesta has been out of baseball for the past decade.