In 2001-2008, he worked in the audit and business advisory department of Ernst&Young, where he recently held a Manager position. Marcin has been a certified auditor registered in the Association of Chartered Certified Accountants in the United Kingdom since 2004. He is also a certified internal auditor (CIA) and has been a member of the Institute of International Internal Auditors since 2006. Associate Member of the Association of Certified Fraud Examiners (ACFE).

Marcin took part in numerous projects relating to audits and reviews of financial statements, both stand-alone and consolidated, drawn up in accordance with the Polish, international (IFRS), German and US accounting principles (US GAAP). He also gained significant experience working on various advisory engagements relating to accounting advisory services, review, assessment and recommendations on improvement of internal control processes as well as due diligence of medium size and large enterprises – often leaders in their industry on the Polish and international markets. Marcin has also experience in capital market projects.

In 2006-2008, Marcin was a technical trainer on audit and review methodology used by Ernst&Young for newly recruited employees in Central and Western Europe.

In 2008-2009, Marcin was a Finance Director and a member of an Executive Team in a joint-stock company with foreign capital belonging to the Eurocash Group.