After finishing her studies, Margje de Koning made all sorts of documentaries for many different broadcasting companies for 12 years.
In 2004 Margje de Koning became a part time teacher at the Culture & Media studies (department Film& Television at the University of Amsterdam).
In August 2004, Margje de Koning became Commissioning Editor for a documentary slot of 52’ docs. This meant producing and co-producing creative single 52'-documentaries.
Since January 2005 Margje de Koning was responsible for the Television Department of IKON and on January 2012 she became Head of TV, Radio and New Media programming at IKON. From January 2016 IKON has been incorporated within EO with Margje de Koning as Commissioning Editor Documentaries for EO, JDocs and IKONdocs. Since June 2019, Margje has been artistic director of Movies that Matter.