Since 16 of January 2020 he is Head of Unit A/2 in DG CNECT responsible for policy development and coordination with regard to Artificial Intelligence. 

Beforehand since November 2015 Kilian Gross was a member of the Cabinet of Commissioner Oettinger. Within the Cabinet, he was mainly responsible for the Commission Anti-Fraud Office (OLAF) and the Directorate-General Human Resources and Security (DG HR). When Commissioner Oettinger was responsible for the Digital Economy and Society, Kilian Gross took care of research, the data economy, e-commerce, innovation and infringements.

From February 2010 until 2015, Kilian Gross was Deputy and Acting Head of Unit of Unit A/1 within Directorate-General for Energy (DG ENER), which was dealing with general policy coordination in the energy sector, planning and programming and legal questions. During his time in DG ENER the Unit has in particular prepared the Energy Roadmap 2050 and the Energy Framework for 2030. Beside the policy work, Kilian was namely responsible for the creation and management of a legal team within Unit A/1.

Before joining DG ENER in 2010, Kilian Gross was a member of the Legal Service of the European Commission. He was mainly responsible for tax issues and later for state aid files.

Kilian Gross started his professional career as an in house lawyer mainly for competition law issues. He is a German lawyer by training with a strong specialisation in European and international law.