Commissioner Roby joined the GDVS in 1994 as Manager of the Griffin Veterans Field Service Office. He worked in that capacity until he was appointed Area II Supervisor in 1998, then North Georgia Regional Director in 2007. He was appointed Assistant Commissioner of Field Operations & Claims in 2012. Beginning Aug. 18, 2014, he served as Temporary Assistant Commissioner in Charge while Commissioner Pete Wheeler was on medical leave, then as Interim Commissioner following Commissioner Wheeler's passing on April 21, 2015.

Prior to his career with the GDVS, Commissioner Roby served in the U.S. Army from 1971 to 1994. He served in aviation and infantry units in Germany and Korea. He also served at U.S. Army Forces Command Headquarters at Fort McPherson, Georgia, and at Department of Army Headquarters in Alexandria, Virginia. He retired as a Sergeant Major on June 30, 1994, while serving as the J1 Sergeant Major, Headquarters Forces Command, Fort McPherson, Georgia. He is a graduate of the Sergeants Major Academy Class 38, Fort Bliss, Texas.

Commissioner Roby was a member of the National Association of State Directors of Veterans Affairs and served as the vice president of the NASDVA Southeast District from 2015 until February 2019. Commissioner Roby was appointed to serve on the State Workforce Development Board, Governor Deal's Census 2020 Complete Count Committee, and the University Advisory Council at Middle Georgia State University.

Commissioner Roby received several awards, including the 2016 Marvin Myers Leadership award, presented by the Georgia Veterans Day Association; the 2017 Eli White Trophy, presented by the Old Guard of the Gate City Guard of Atlanta; and the 2019 Joe Barto Award, presented by the Georgia Military Officers Association.

In 2020, Commissioner Roby was selected as the 130th inductee in the Georgia Military Veterans Hall of Fame.

Commissioner Roby's father, Robert Roby, Sr., was a retired Army Sergeant Major and Vietnam War veteran who also served overseas in Germany, Korea, and South America. Commissioner Roby's three brothers all served on active military duty. Collectively, the Robys spent 107 years in uniform.

Commissioner Roby is an avid sports fan and has a passion for vintage classic cars. He has been married to his high school sweetheart, Terrie, for 49 years. They have one son, Michael, Jr.; one daughter, Jennifer; and three grandchildren, Lucas, Anna, and Drew.