A political science graduate, she began her professional career in 2012 at the European Parliament working with a French MEP on health-environment issues. In 2017, after gaining experience in a start-up specializing in ecomobility projects, she spent two years at the French National Assembly, where she worked on the Sustainable Development and Spatial Planning Committee.

In early 2019, she joined the cabinet of Elisabeth Borne, then Minister in charge of Transport; she then followed her to the Ministry of Ecological Transition and Solidarity as a parliamentary advisor.

At the end of 2020, she joined the SNCF Group as head of institutional relations at Rail Logistics Europe.

In 2022, Nina Bourgier joined the office of the Prime Minister, Elisabeth Borne, as deputy, then head of the parliamentary department.

On March 20, 2024, she was appointed Chief of Staff to the General Management of SNCF Gares & Connexions and joined the Executive Committee.