Kajsa Ollongren started her career in the civil service at the Ministry of Economic Affairs, becoming a economic policy advisor in the area of Central and Eastern Europe in 1992, in which capacity she developed economic cooperation programs with various Eastern European countries after the fall of the iron curtain. She was head of parliamentary affairs within the ministry until 2001, and director of European Integration and Strategy from 2001 to 2004, and became Deputy Director General of the ministry in 2004. In 2007 she moved to the Prime Ministers Office, also the Ministry of General Affairs, to become the Deputy Secretary General and in 2011 Secretary General of the ministry and the most senior advisor to the Prime Minister. In that capacity she was also responsible for the coordination of the Dutch intelligence services and she chaired the weekly meeting of the secretaries general. After the 2014 local elections Kajsa Ollongren became an alderwomen and first deputy mayor in Amsterdam. Her portfolio included economic affairs, seaport, airport, art, culture, local media, monuments and the city centre. On 26 October 2017, Kajsa Ollongren was appointed as Minister of the Interior and Kingdom Relations. She was also Deputy Prime Minister in the third Rutte government. From 10 January 2022 until 02 July 2024, Kajsa Ollongren was the Minister of Defence in the fourth and last Dutch government headed by Mark Rutte.