Graduate of the Faculty of Law of the Adam Mickiewicz University in Poznan, upon the completion of his judge training and passing the judicial exam, adjudicated in the Civil Department and Land Registry of the Regional Court, and then in the Civil Appeal Department of the District Court. As of 1998, judge of the Finance Chamber of the Supreme Administrative Court; initially adjudicated in cases of income tax and execution of administrative decisions, and as of 2007, in cases related to goods and services tax. Currently, Chairman of the Judicial Information Department of the Supreme Administrative Court.
In the years 1994–1998, member of the Presidium of the National Council of the Judiciary, and as of 2014, Deputy Chairman of the National Electoral Commission.
Characterized by extensive practical experience and expertise in the field of civil law and civil proceedings, in particular non-litigious and executive proceedings, and additionally, the law of real estate and real estate register. Judge-rapporteur in cases regarding questions referred for a preliminary ruling to the Court of Justice and resolutions of the composition of seven judges of the Supreme Administrative Court. He participated in issuing several thousand tax rulings and preparing their justifications. For a number of years, a valued lecturer at training courses dedicated to tax advisors, solicitors and legal advisors, as well as tax administration employees. Furthermore, member and chairman of the team developing questions and tasks for legal trainings and legal examinations, member of examination boards, member of the State Examination Board for Tax Advisory Services. Member of the Editorial Board of „Przegląd Podatkowy”.
Chosen Publications:
S. Marciniak, Uwagi do zmian w ustawie - Prawo o postępowaniu przed sądami administracyjnymi, „Przegląd Podatkowy” 2010/9
S. Marciniak, Termin wydania indywidualnej interpretacji przepisów prawa podatkowego, „Przegląd Podatkowy” 2010/6
S. Marciniak, Odpowiedzialność członków zarządu za zaległości podatkowe spółek kapitałowych (art. 116 ordynacji podatkowej), „Przegląd Podatkowy” 2009/12
S. Marciniak, Pięć lat funkcjonowania sądu odwoławczego w sprawach zobowiązań podatkowych, „Przegląd Podatkowy” 2009/6