Brigadier-General Stack began his military adventure in high school with 2415 Gonzaga Royal Canadian Army Cadet Corps. He joined the Canadian Forces Army Reserve in 1978. He has served as the Commanding Officer of 56 Field Engineer Squadron, G3 Newfoundland District, G9 Land Force Atlantic Area Headquarters, and Commander of 37 Canadian Brigade Group.
He is a graduate of the Army Command and Staff College in Kingston and the Canadian Forces College in Toronto as well as Memorial University of Newfoundland where he obtained a Bachelor of Education (Secondary), a Bachelor of Science (Mathematics), and a Master of Education (Leadership).
In 2004, Brigadier-General Stack served as the Chief of Civil Military Cooperation Operations for the NATO-led International Security Assistance Force in Kabul, Afghanistan.
In November 2008 he was promoted to his present rank and assigned the position of Deputy Commander Land Force Atlantic Area, a position which he still retains. From January until September 2010, Brigadier-General Stack took a leave of absence from his civilian career and was assigned full Command of Land Force Atlantic Area.
In the fall of 2010 he served as Commander Joint Task Force (NL) during OP LAMA, a Canadian Forces domestic humanitarian relief effort providing assistance to the province of Newfoundland and Labrador in the wake of Hurricane IGOR.
Brigadier-General Stack is employed as a Senior Education Officer with Eastern School District. He enjoys spending time with his wife Wanda, running, reading, and watching his son Shane compete in basketball and volleyball.