The Mandaat team

We work as part of a strong team. Our team has people that supplement and enhance each other. A unit of co-operative, driven professionals. People that work hard and play hard, for great results and lots of fun.

Mandaat’s Managing Partners

Diederik van den Biggelaar and Janco Duvekot know what it’s like to break a sweat. Diederik explains. ‘A personal approach is self-evident to us, precisely because we have years of experience, including as entrepreneurs. We know what responsibility means, the strains upon a businessperson. So we can quickly sense what our client is looking for.’

Diederik van den Biggelaar

Managing Partner

Diederik began his entrepreneurial career when he was still at university, as one of the founders of renowned student disco Dansen bij Jansen in Amsterdam. He then moved on to the international world of business, working at Heineken for an extended period of time. He worked in the bars & hotels branch as well as the international branch. He left Heineken as the chief export manager for Europe and Japan.
After Heineken, Diederik worked at Samas as group executive, GM at De Boer Temporary Structures, owner-manager of Perfecta, founding partner of iKi Beer, and as senior partner at Custom Management. He has been one of the owners of Mandaat for over 9 years now.

Janco Duvekot

Managing Partner

Janco comes from a Sales and Marketing background, with experience at Heineken. He started out there after studying business economics in Rotterdam. At Heineken, he acted as commercial executive at Vrumona, the largest supplier of fizzy drinks in the Netherlands. He moved on as an independent manager in the Business Development arena. He also fulfilled several positions in manager/training coach roles in field hockey. He joined Mandaat in 2012 and developed the Flexpat model, which is all about interim management in locations across the world.
Janco has established himself as the lynchpin of Mandaat’s International Desk. With Mandaat joining the WIL Group, the London-based Worldwide Interim Leadership Group, Janco has become a leader regarding their cross-border placements within the Dutch business community.

Associates

Jeroen Nuesink and Wim Slot. Jeroen started out at then-ABN Bank. He then became a consultant at Boer & Croon. After that, Jeroen put his experience to good use in leading roles at Rodenstock and then KCFS Corporate Fashion. Jeroen has worked as an interim manager since 2002 and has been a partner at Custom Management for a number of years.

Wim started out in accountancy. Soon after, he became a finance manager at a number of firms. He went into interim management in 1995 and has developed into of the the most experienced finance and general executives of Mandaat, dedicating himself to such diverse arenas as bankruptcies, rehabilitations, family feuds, cultural differences, and dealing with major incidents of corporate fraud.

Jeroen Nuesink

Associate

Jeroen started out at then-ABN Bank. He then became a consultant at Boer & Croon. After that, Jeroen put his experience to good use in leading roles at Rodenstock and then KCFS Corporate Fashion. Jeroen has worked as an interim manager since 2002 and has been a partner at Custom Management for a number of years. Additionally, he was shareholding executive of Kerstholt Teak Deck Systems until 2010.
The interim management assignments that Jeroen has taken on mostly concern change management. He has taken up projects in many different industries, and usually in situations that required action, often rather immediate.
After partnering with Diederik van den Biggelaar for 8 years until 2017, Jeroen continues to be attached to Mandaat in an associate role.

Wim Slot

Associate

Wim started out in accountancy. Soon after, he became a finance manager at a number of firms.
He went into interim management in 1995 and has developed into of the the most experienced finance and general executives of Mandaat, dedicating himself to such diverse arenas as bankruptcies, rehabilitations, family feuds, cultural differences, and dealing with major incidents of corporate fraud.

Office Management

We rely completely on Dorinde to organize and manage Mandaat’s back office. After the middle school for administration and business (meao) and the NVM real estate course, Dorinde worked in several roles in real estate and was involved in project management, in multiple roles. At Mandaat, Dorinde cares for our financial administration and organizes our Mandaat events and other gatherings. Dorinde also manages regular contacts with suppliers.

Dorinde Wiersma-Gerwig

Office Manager, a.i.

We rely completely on Dorinde to organize and manage Mandaat’s back office. After the middle school for administration and business (meao) and the NVM real estate course, Dorinde worked in several roles in real estate and was involved in project management, in multiple roles. At Mandaat, Dorinde cares for our financial administration and organizes our Mandaat events and other gatherings. Dorinde also manages regular contacts with suppliers.