She began her career at Procter & Gamble where she worked for 16 years in different countries and where she was responsible for major brands. In 2000, she became vice president of marketing & innovation at Electrolux Europe and in 2005 she started as chief marketing officer at Philips Lighting.

Mrs. Janssen currently is the CEO and chair of the board of management of Ecorys, a leading international research and advisory company, which assists private and public leaders in making informed choices with regard to social, spatial and economic issues. In addition, she chairs several expert committees in the field of energy transition and climate change, and is a director at GIMV.