Before assuming the current position in 2018, Lieutenant General Ken Sosavoeun was assigned to be the United Nations Military Observer in Sudan. During his assignment there, he had been promoted to be Team site leader of sector II and WAU Team site from 18 July 2007 to 19 July 2009. After the completion of UN Mission, LTG. Sosavoeun was vetted and approved for Senior Mission Leader Program in Japan and in the United States in 2010.
From 2005- 2006, he was assistant to the cabinet of Deputy Prime Minister, Minister of National Defense. In 2004, he was sent to the state of Hawaii, United States of America for a counter-terrorism training course. From 1992 to 2004, he was the Training Chief of Intelligence Department. From 1989 to 1991, He had been deployed at Thai-Cambodia border as an Intelligence officer. He joined army in 1979 as Junior Intelligence officer. LTG. Sosavoeun held a bachelor degree in Teaching Pedagogy and married with five children.