He served as an interim Minister for National Defence in the Caretaker Cabinet of Vassiliki Thanou-Christophilou.

[2] His initial assignment was in the 117 Combat Wing stationed at Andravida Air force Base, as an F-4 Phantom II aircraft pilot.

Air Chief Marshal Giangos served as Staff Officer in the plans and policy branch at the Supreme Headquarters Allied Powers Europe (SHAPE) in Mons, Belgium and as Commander of the NATO Combined Air Operations Centre-7, in Larissa, Greece.

[2] In September 2009, during discussions with Supreme Allied Commander Europe, U.S. Admiral James Stavridis, Giangos outlined the country's positions concerning participation of Greece in NATO peace-keeping missions as well as the present situation of the Aegean dispute.

Giangos was appointed as the interim Minister for National Defence in the Caretaker Cabinet of Vassiliki Thanou-Christophilou on 28 August 2015.