As a veteran in the banking industry for nearly 40 years, he started his career in 1971 with Citibank for more than ten years and became Vice-President. He held director positions in several major banks since then, including Executive Director of Bank Central Asia and President Director of Bank Lippo (CIMB Niaga). His extensive experience has also brought him to the commissioner seat for many companies, including PT Lippo Securities, PT Indosat (Persero), PT Jamsostek (Persero), and Bank Mandiri (Persero). Markus also held public service roles within the State-Owned Ministry, including as the Assistant of the Minister for Public Service and Human Resource Development in 1998 and for Finance and Other Services from 1998 to 2000. Markus served as President Commissioner for PT Star Pacific Tbk between 2009 and 2013 and as a commissioner for PT Bank Nationalnobu from 2012 to 2017.