Martijn Peters

Martijn has 20 years of experience in M&A and strategy consulting. Before founding DEX in January 2015, Martijn was partner and vice-president at international consultancy firm Solving Efeso (now Efeso Consulting), where he was head of the international M&A practice. Martijn started his international career with Sara Lee in the Netherlands and Brazil. He studied business administration at the University of Groningen, marketing at UCLA in Los Angeles, financial management at the University of Amsterdam and completed executive courses at Harvard Business School in Boston and Kellogg Business School in Chicago. Martijn has a broad experience as an international deal maker and is the president of Globalscope.

Koen Andeweg

Koen is a seasoned advisor and deal maker with international experience in various industries including software, ICT, business services, manufacturing and pharma.

Prior to joining DEX international M&A in 2015, Koen was Corporate Finance & Strategy Consultant at Efeso Consulting and business development manager at EY. Koen started his career in Investor Relations at the Siemens Corporate Headquarters in Munich. He studied business administration at the Erasmus University in Rotterdam and the San Francisco State University and completed executive education courses at Kellogg Business School in Chicago.

Floris de Klerk

As a passionate sailor, Floris started his professional career at Nautor’s Swan Benelux. He gained experience from a wide range of assignments including management of international yacht racing campaigns and facilitating international transactions of sailing yachts. Joining DEX in 2017, Floris adapted his years of specialized client relationships to the M&A industry, using the same qualities to deliver for his clients today.

Floris studied Business Engineering in Amsterdam and Management at Nijenrode Business University, including course at Universidad de Los Andes in Bogota, Colombia.

Kees-Jan van 't Westeinde

Kees-Jan has been a partner at DEX since 2026, after founding his own M&A boutique Westeinde Business Builders in 2019. He has more than 25 years of international M&A experience, with a strong focus on building materials. During his 20 years at CRH plc, he developed into a strategic and experienced dealmaker with deep commercial and operational business knowledge. His strength lies in guiding entrepreneurs in one of the most decisive phases of their lives: the transfer of their life’s work to a suitable new owner. In doing so, he has an explicit eye for both the business and the personal and emotional aspects of the process. Kees-Jan studied Business Econometrics at Erasmus University and followed executive programs at Michigan State University and INSEAD, among others.

Besides his professional life, Kees-Jan is happily married to Elise and proud father of two adult sons, Okke and Tijn. In his free time, he enjoys traveling to distant places, sailing, hiking, and nice dinners with family and friends – preferably accompanied by a good glass of wine.

Mark Klein Haneveld

Mark joined the DEX team in 2017 and has since worked on assignments in a wide range of industries. He has a Master’s degree in Finance from Tilburg University. During his Bachelor’s program, Mark studied abroad gaining international experience at the Chinese University of Hong Kong.

Mark began his career with DEX as an analyst and is currently manager M&A.

Sjoerd Ebbing

Wencke Willemze

Wencke joined DEX as our office manager, bringing with her the experience she gained in the professional services industry with firms such as Interpolis, De Hypotheker, and Audax.

Wencke specialized in Linguistics and Artificial Intelligence while she studied Communication/Information Sciences at Tilburg University. She also completed a study in Graphic Design.

Julius Buwalda

Mathieu has been working as a working student at DEX since early 2025, where he supports various projects.

After completing his International Baccalaureate at UWC Atlantic College in Wales, Mathieu went on to study at Erasmus University Rotterdam, where he obtained a BSc in Economics & Business Economics. He is currently pursuing an MSc in Financial Economics, which he is expected to complete this year.

Mathieu Dullaert

Julius was born and raised in Johannesburg, South Africa, and moved to the Netherlands to complete the International Baccalaureate in Oegstgeest. He gained professional work experience as an analyst at Aegon Asset Management and Auxilium Capital Private Equity before joining DEX International M&A in April 2025.

He earned an MSc in Financial Economics from Erasmus University Rotterdam and is currently pursuing a second BSc in Philosophy at the same university, complementing his first BSc in Economics and Business Economics.

Maarten de Nooijer

Maarten de Nooijer joined DEX at the end of 2024, bringing a background in Reservoir Engineering from TU Delft. During his time at the university, he served as Chairman of the Central Student Council and completed a minor in Australia at the University of Technology Sydney. In addition, he contributed to two international energy projects focused on green hydrogen in India and geothermal energy in Spain, working with ING and Repsol, respectively.

While his foundation is technical, Maarten has always been driven to broaden his financial expertise. At DEX, he continues to build on this interest and further developing his financial skill set.