Peter Jun
Chair and Elected Trustee
Peter was elected to the Supervisory Board in 2018. He earned an MA in International Relations, with high honors, from the University of Amsterdam and a BA in Government (Political Science), cum laude from Harvard College (University).
Peter has been active in professional real estate investing since 1999. Peter also served on the Board of Trustees at the International School of Zug and Luzern (Switzerland). He has one ISA alumni child and two children still attending ISA.
Peter was born in South Korea and is a dual US and Dutch national.
Maaike Siemons
Secretary and Appointed Trustee
Maaike was appointed to the Supervisory Board in 2020. Born and raised in the Netherlands, she has lived in Vienna, Singapore and Düsseldorf. Maaike is married to Frans and together they have three sons.
After earning a degree in Law from the University of Utrecht, she started her career in Finance with Fortis Bank in Utrecht and ING Bank in Vienna. From 1998 she trained to be a personal coach and mediator and worked for Raymakers Van der Bruggen. In 2006 the family moved to Germany, where the boys joined the International School of Düsseldorf. Maaike has been involved in International School Governance since 2008. The family moved back to the Netherlands in 2017 and the youngest son Casper joined ISA and graduated in 2019.
Celeste Gibbens
Elected Trustee
With nearly two decades of international marketing leadership experience across multinational technology organisations, Celeste has built a career driving growth, innovation, and transformation across the Middle East and Africa. Having recently relocated to Amsterdam after 12 years in Dubai, she most recently served as Regional Marketing Director for Lenovo’s Intelligent Devices Group in the Middle East, leading multinational marketing, communications, and brand initiatives.
Known for combining strategic vision with a pioneering mindset, Celeste has led high- impact programmes across diverse international markets and has been a strong advocate for advancing women in leadership, mentoring emerging talent, and fostering inclusive cultures within the technology industry.
As a mother of three children, including twins, Celeste brings both a global perspective and a deep personal commitment to education. She joins the ISA Supervisory Board with a focus on long-term impact, supporting strong governance, sustainable growth, and the continued evolution of ISA for future generations.
Esmond Douma
Appointed Trustee
Esmond was appointed to the Supervisory Board in 2022. He has always lived in the Amsterdam and Amstelveen area. Esmond earned his degree in Dutch Law from the Vrije Universiteit (Free University) in Amsterdam. For more than 25 years, Esmond has been a barrister and is specialised in employment law. Esmond has a sound track record regarding board memberships: e.g. Amstelveen Entrepreneurs Association, Golf club Olympus, parents teacher association primary school De Horizon in Amstelveen, Platform C in Amstelveen (music school, people’s university, art). Esmond is married to Jenny (born in Malta), and together, they have twin sons. Esmond loves (playing) soccer and golf.
Tex Gunning
Appointed Trustee
Tex Gunning is an international business leader with extensive executive and board experience across Europe and Asia. Having held senior leadership roles, including President of Unilever Asia and CEO positions in several multinational organizations, he brings deep expertise in strategy, governance and organizational transformation.
Tex is passionate about education and values-based leadership and believes that strong character and lifelong learning are essential for success. As a member of the Supervisory Board of the International School of Amsterdam, he looks forward to supporting the school’s continued pursuit of educational excellence and preparing students to thrive in an increasingly global and AI-driven world.
Remko Vochteloo
Appointed Trustee
Remko was appointed to the Supervisory Board in 2023. Remko currently serves as the COO/CFO at Business Models Inc, a full-service strategy and innovation agency. He has been a board member of ISH (International School of Hyderabad).
He holds the title of Qualified Controller and completed his MBA at the Business School Lausanne. Additionally, Remko pursued Data Science studies at IIIT Bangalore. Over the course of his career, he dedicated 28 years of service to renowned firms such as Arthur Andersen and Deloitte. During those years, he spent 11 years working in Hyderabad, India.
Remko has two children, a son, and a daughter, aged 23 and 24, respectively. They both had the privilege of attending prestigious schools in Hyderabad and The Hague.
Besides his professional commitments, Remko is actively involved in advisory roles. He serves as an advisor to the American International School in Lusaka and The Mahindra International School Pune. Additionally, he actively participates in various Advisory Boards encompassing FinTech, AI, and NGOs, with engagements in Cambodia, Indonesia, the UK, and the US.
Arielle Ruys Strem
Appointed Trustee
Arielle is a digital executive with over 25 years of experience at McKinsey & Company and Nike, where she held global and regional leadership roles focused on building iconic brands and driving strategic growth. She brings board-relevant expertise in strategy, finance, and organisational transformation, as well as governance experience from her prior service on the supervisory board of a U.S.-based school. She holds a B.A. in Urban Planning and Architecture from Brown University and an M.B.A. from Columbia Business School.
In addition to her corporate career, Arielle is a certified birth doula (DONA) and recently re-established her maternal wellness practice, Core Birth Collective. Arielle and her family rejoined the Amsterdam community in 2024 after several years abroad. As parents they have experienced the lower, middle and upper school programmes and currently have a 7th grader enrolled at ISA.
Nina Dombrowska
Appointed Trustee
Nina and her family moved to Amsterdam in 2022. In the meantime two children have already graduated from ISA while the youngest one will be moving to grade 8.
Nina brings over 20 years of international business experience to board-level governance, with particular strength in strategy, organisational transformation, marketing and brand-building across consumer markets. She has served as a board member and chair across several companies, giving her a practical understanding of what effective oversight looks like from both sides of the table.
Her entrepreneurial experience — co-founding a consumer goods business taught her risk-taking under pressure, lean financial management, and building something from scratch in difficult conditions.
Nina is also active in advancing governance practice more broadly: she co-founded an organisation supporting women’s leadership in governance and teaches inclusive leadership in professional governance programmes.
Norman Metzner
Appointed Trustee
Norman and his family joined the ISA community in 2025, and he has three children entering Grades 7, 5, and 3.
He has a professional background in consulting and entrepreneurship with over 12 years in executive leadership roles spanning Europe and Asia. As the Country CEO of an InsurTech company, he works at the forefront of digital and AI, and in his prior role as a consultant, he advised financial services companies on a wide range of topics, including strategic transformations and technology. Norman is excited to contribute to the Board with practical insights on technology, innovation and strategic direction.
Complementing his professional experience, Norman has served as a Board Governor at the Alice Smith School in Malaysia, where he chaired the Digital and Technology subcommittee and was a member of the Finance subcommittee.