Mr. Johnson Mwangi Maina has served the Government of Kenya for over 26 years as an Economist, where he joined at the entry grade of Economist II. Since joining service he has served in various Government Ministries/Agencies including Office of the Vice President and Ministry of Planning and National Development, Ministry of Finance and Planning, Ministry of Environment and Natural Resources, Ministry of Education Science and Technology, Ministry of Health  and The National Treasury.

In the 26 years, he has managed to rise up the ladder as a career civil servant to the current grade of Director of Planning/Senior Deputy Director, Macroeconomics and Fiscal Affairs Department in The National Treasury. In addition, he is a Director at the Kenya Leather Development Council and the Tom Mboya University  as alternate to the Cabinet Secretary of The National Treasury.

He studied at the University of Nairobi and obtained a Bachelor of Arts in Economics Degree, Upper Second Class Honours and Master of Arts in Economics degree. In the course of his tour of duty, he has undergone extensive professional training by the government, the Development Partners and other institutions including by Oxford University, World Bank, United Nations, International Monetary Fund, Kenya Institute of Public Policy Research and Analysis (KIPPRA), Institute of Policy Analysis and Research (IPAR) and Kenya School of Government (KSG) among others.

He is the alternate to the Principal Secretary for the time being responsible for Finance.