In 1994-1998 Daniel studied at Kiev National Economic University where he obtained a Bachelor’s Degree with honors in Economics and a Master's Degree in Business Management. He continued his studies at the Association of Chartered Certified Accountants (ACCA), is a bearer of the IFRS International Certificate, Auditing and Financial Management Certificate and is a member of the Supervisory Board of ACCA Ukraine.
From 1998 to 2001 Mr. Maydanik worked as an expert certified by the State Property Fund of Ukraine in cost evaluation and management consulting.
In 2001 started his career as an auditor and financial consultant with Deloitte which is among the "Big Four" accounting firms. Soon afterwards Mr. Maydanik was appointed as a top executive manager.
In 2007-2009 he moved to the position of Deputy CFO with Interpipe – one of the largest Steel pipe and railway wheel producers in the world.
Since 2009 up to the present day D. Maydanik has been the Head of Corporate Finance and Investment Management Department, representative of the EastOne Group Board of Directors, where, in particular, he is in charge of oil and gas area of activity.
In December 2015 Mr. Maydanik was elected a Chairman of the Board of the Association of Gas Producers of Ukraine which incorporates seven largest gas producing companies of Ukraine – UkrGasVydobuvannya, DTEK Neftegaz, Burisma, Geo Alliance Group, Smart Energy, KUB-Gaz and Poltava Petroleum Company.