Hernandez assumed the position upon its activation on October 10, 2010, with its headquarters at Fort Belvoir, Virginia.

During his career, he held posts with numerous field artillery units as well as a number of staff officer positions.

Hernandez was the Assistant G-3/5/7, Headquarters, Department of the Army; the Chief, United States Military Training Mission in Saudi Arabia; and the Commander, United States Army Human Resources Command.

Hernandez also attended the University of Virginia, where he received a master's degree in Systems Engineering and he attended the National War College where he received a master's degree in National Security and Strategic Studies.

Hernandez oversaw a command that brought an unprecedented unity of effort and synchronization of all Army forces operating within the cyber domain.