Jan Willem started working at Sotheby’s in Amsterdam in 1986, in the Arcade Department. Throughout his tenure in Amsterdam, he headed the European Ceramics Department, the Furniture Department and later the Decorative Arts Department. In 1996 he was appointed Deputy Director and in 2001 he was promoted to Director, concentrating on valuations across Europe, where he was able to initiate the first of the Garden sales in Amsterdam. He then moved to the Munich office and concentrated on the sales from various European Castles and Noble and Private collections, the sales of which were held four times a year in Amsterdam. These sales included the collections of the estate of HRH Queen Juliana of the Netherlands, HRH Princess Christina of the Netherlands, the estate of HRH Princess Lillian of Belgium, the Royal House of Hanover and all the important House collections in Germany, Belgium, the Netherlands, Corsica and Malta, with perhaps the greatest experience being the Collection of the Royal House of Hanover and the Collection of Lily & Edmond J. Safra.
In 2008 Jan Willem moved to New York as Vice President and head of the European Furniture Department. From 2019 to 2021 he moved to London to work on the Sotheby’s online appraisal platform as Senior Specialist Appraiser.
He returned to New York in November 2021 and re-joined the European Furniture department, as Senior Specialist. Throughout his career, his greatest focus was and still is on Collections, with a special focus on European Furniture and Ceramics.