Dyomin supervised the development and adoption of the regional complex program of social and economic development of Kharkiv oblast till 2010. Since 2000, he was the Secretary of the National Board on coordinating general state and regional bodies and local authorities.

Dyomin is a member of the Supreme Economic Board under the Office of the President of Ukraine (1997-2001); a member of the Board of Overseers of the National Foundation of Social Protection of Mothers and Children “Ukraine for Children” (2001).

In 2006-2008, Dyomin was the Ambassador Extraordinary and Plenipotentiary of Ukraine in the Russian Federation and in 2008-2010 — the Director of the Institute of International Relations of the National Aviation University (Kyiv).

In 2010-2013, Dyomin was the Ambassador Extraordinary and Plenipotentiary of Ukraine in the Republic of Kazakhstan, since 2013 — the Ambassador Extraordinary and Plenipotentiary of Ukraine in the People’s Republic of China.

Titles

President of the Federation of Swimming in Ukraine, member of the Executive Committee of the National Olympic Committee of Ukraine, Honorary Citizen of Kharkiv (2006) and Kharkiv oblast (2012).

Awards

Laureate of State Prize of Ukraine in Science and Technology (2002).  Order of Merit, Class III (1997), Class II (2002), Class I (2011), Order of Prince Yaroslav the Wise, Class V (1998).