 Keller began her career at the Ministry of Agriculture between 1985 and 1988 and was responsible for the management of the French cereal market, moving on to the Ministry of Finance (Treasury Department), where she was responsible for funding agriculture and fisheries.In 1989, Keller was appointed CEO to the CIAL bank (Crédit Industriel d'Alsace Lorraine), and then, in 1996, General Manager of Crédit Commercial de France (CCF), which she left in 2001, the year of her election as mayor of Strasbourg.In addition to her work in local politics, Keller served on the Senate from 2005 until 2019.