[2] Serafin began his professional career at the Office of the Committee for European Integration (UKIE) in 1998.

Between 16 January 2008 and 31 December 2009, he was Undersecretary of State at UKIE and National Aid Coordinator for the Phare and Transition Facility programmes.

[2] In February 2010, Serafin was appointed the deputy head of Cabinet of the EU Commissioner for Financial Programming and Budget Janusz Lewandowski.

On 1 December 2014, Serafin took the position of the Head of the Cabinet of the President of the European Council, Donald Tusk.

[3][4] From 13 December 2023 to October 2024, Serafin served as the acting Permanent Representative of Poland to the European Union.