Prior to his recent appointment, DeCosta served as the Director of Player Personnel for the Ravens, being heavily involved in both college and pro scouting. Before that, DeCosta was the Director of College Scouting in Baltimore, where he oversaw the NFL draft. DeCosta, who began his career in the National Football League as a Player Personnel Assistant in 1996, served as Mid-West Area Scout from 1998-2003. For the past seventeen years, DeCosta has worked for General Manager Ozzie Newsome, a member of the Pro Football Hall of Fame.
DeCosta attended high school at Taunton High School (Taunton, Massachusetts) and played football at Colby College, where he served as team captain in 1992 under head coach, Tom Austin. A Dean's List student who graduated with honors, DeCosta earned bachelor of art's degrees in English and Classical Civilizations in 1993. In 1996, DeCosta received a Master's degree in English from Trinity College, Hartford.
Prior to his stint in the NFL, DeCosta worked at Trinity College (1993–1996) as a Graduate Fellow, coaching football in the Athletic Department.
Named as one of the most powerful people in sports under the age of 35, DeCosta has played a strong role in the drafting of Pro Bowl players like Ed Reed, Terrell Suggs, Jamal Lewis, Bart Scott, Le'Ron McClain, Haloti Ngata, Marshal Yanda, Ben Grubbs, and Ray Rice along with significant contributors Tony Weaver, Mark Clayton, Chester Taylor, Ed Hartwell, Dawan Landry, Jason Brown, Jared Gaither, Sam Koch, and Lardarius Webb.
In April, 2008, DeCosta and the Ravens traded the 8th pick in the 2008 Draft to the Jacksonville Jaguars for the 26th pick in the first round and other picks. The Ravens then traded the 26th overall pick and their third round pick to the Houston Texans for the 18th pick, where the Ravens then selected 2008 Diet Pepsi Rookie of the Year winner, QB Joe Flacco from the University of Delaware. In his first season as Ravens starting quarterback, Flacco led the Ravens to the AFC Championship Game, where they lost to the eventual Super Bowl Champion Pittsburgh Steelers.
The next year, in April, 2009, DeCosta and Newsome traded the 26th pick in the 2009 Draft and another pick to the New England Patriots for the 23rd pick in the first round. The Ravens then selected 2009 Offensive Rookie of the Year runner-up Michael Oher, OT, from Ole Miss. Oher was featured in Michael Lewis' acclaimed book, The Blind Side: Evolution of a Game which was also made into a movie starring Sandra Bullock.
One year later in March 2011, in an interview at the annual Owners' Meetings in New Orleans, Louisiana, Ravens owner Steve Bisciotti referred to DeCosta as General Manager Ozzie Newsome's eventual successor.
DeCosta was on the radar for several teams with General Manager openings following the 2011 season including serious interest from the Chicago Bears. However in January 2012 DeCosta signed a new contract with Baltimore that would make him one of the highest paid executives in football and ensure that he stayed on as Ozzie Newsome's eventual replacement.