Focus on simplicity
Digitization creates new opportunities, but also risks. In recognizing these risks and taking appropriate measures, we often see too little focus on simplicity. Standards are no longer the checklists we used to know. Information security is a continuous process that is all about maintainability and acceptance. Nestor Security will help you create and maintain an up-to-date policy that fits your organization and moves easily with changes.
Marcel Dusink
RE IT and ISO auditor
"Nestor Security focuses on implementing a risk-based approach. We ensure that organizations can keep moving in a more complex digital environment. As an IT and ISO auditor, I have had the opportunity to assess a large number of organizations for their effectiveness in security. I often see too little focus on simplicity, a clear approach and quality. From this vision we at Nestor Security guide and train our security professionals. Our team offers a powerful solution for improving the security maturity level of your organization."
Ad van 't Hoenderdal
Consultant & auditor ISO27001/NEN7510
"Standards today are no longer checklists as we know them from the past. The starting point is a risk analysis, and as soon as circumstances change, the organization will have to respond. And that always continues; you are never definitively finished. That is why you should not make the so-called management system too complicated, because that is at the expense of maintainability and - hence - acceptance. I like to help organizations shape information security in a way that stays close to the important business processes and leads to a higher quality of service."
What we stand for
We maintain an open culture of honesty, transparency and diligence
Growth is not a goal, but a consequence of performing a little better every day
As a flat organization, we value an informal work atmosphere; we also convey this to customers
We do not think in terms of hours,
but in results
We do what we say
and we say what we do
Our team
Our team consists of Security Consultants with many different backgrounds. Because we can combine knowledge from, for example, the healthcare, technical and legal world, we are able to provide organizations with targeted advice.
Marcel Dusink
Consultant & auditor
CISSP for RE,
ISO Lead Auditor
Meet Marcel
As an IT and ISO Auditor, Marcel has already had the opportunity to assess a large number of organizations in the field of security. He often sees in organizations too little focus on simplicity, a clear approach and quality. From this vision we at Nestor Security guide and train our security professionals. Marcel can offer a powerful solution to improve the security maturity level within your organization.
Ad van 't Hoenderdal
Consultant & auditor
ISO 27001/NEN7510 Lead auditor
Meet Ad
Ad is an expert in the field of information security. Since 2007 he has focused on ISO management systems as a certified Data Protection Officer. Ad has guided more than 25 organizations towards obtaining ISO 27001 or NEN 7510 certificates, and performed thousands of internal audits. Besides performing audits, Ad's specialties lie in setting up customized management systems and integrating ISO management systems.
Wendy Sikkema
Security Consultant
ISO 27001 Lead Auditor
Meet Wendy
As an ISO 27001 Lead Auditor, Wendy plays an active role in ISO implementation projects and conducting audits. She also regularly fulfills a security role at various organizations within the IT sector and government agencies. Her expertise further extends to ISO 9001 implementations and achieving CCV certification.
Wendy completed her college education in HBO-ICT with a specialization in Network and Security Engineering and a minor in Privacy Management. As a Security consultant, she can perfectly combine her passion for IT, security and privacy.
Rients van Blanken
Security Consultant
CISM, ISO 27001 Lead Auditor,
Certified Information Privacy Professional/Europe
Meet Rients
Rients' expertise includes ISO 27001 and the AVG. As a certified ISO 27001 Lead Auditor and with his CIPP/e certification, he fulfills the role of Security Officer within various organizations.
With a combination of backgrounds in Business and IT and his previous role as an ERP consultant, he has gained deep insight into organizations, enabling him to have effective conversations and accurately understand customer needs.
Wilbert Hilhorst
Security Consultant
CISA, CISM, Lead Auditor, Comptia Security+, ITIL4 Foundation, SAP System Security and Authorization, SAP Authorization and Auditing
Meet Wilbert
Wilbert has a solid knowledge of information security thanks to his Certified Information Systems Auditor and Certified Information Security Manager certifications. He gets energy from both implementing ISO 27001 and performing audits at a variety of organizations. He can also be deployed as a Security Officer. With his background in International Business, he finds particularly interesting the intersection where effective information security and efficient business processes come together.
Margo Sportel
Security Consultant
ISO 27001 Lead Auditor, Certified Information Privacy Professional/Europe
Meet Margo
Margo's work includes ISO 27001, NEN 7510, and ISO 9001 implementations. In doing so, she is deployed as a security officer at various types of organizations in, for example, the IT market and wind and solar energy sectors. In addition, Margo advises on the AVG and provides training for employees and administrators in the context of NIS2 and the various standards frameworks. With her legal background, she offers an analytical view in the rapidly changing security world.
Marieke Bronsveld
Security Consultant
ISO 27001 Lead Auditor,
Certified Information Security Manager
Meet Marieke
In over 11 years, Marieke has helped several organizations obtain their ISO 27001 certification and make the ISMS appropriate to those organizations. In her career, she worked on drafting security policies and awareness programs, among other things. She also worked with various IT teams on threat assessments and underwent several audits as an auditee.
Marieke can be employed as an ISO, CISO, internal auditor and for individual security assignments.
Storm Koops
Security Consultant
ISO 27001 Lead Auditor
Meet Storm
Within the field of security, Storm's expertise lies in the role of Security Officer and ISO processes. Storm holds an ISO 27001 Lead Auditor certificate and works for a variety of organizations, including government agencies, international providers and SMEs. After completing his degree in Enforcement, Supervision and Security, Storm earned his Bachelor's degree in Integral Security Studies. He now uses his diverse security knowledge to optimize information security for organizations.
Eline Olthof
Security Consultant
ISO 27001 Lead Auditor
Meet Eline
Based on her ISO 27001 Lead Auditor certification, Eline works on various implementations of ISO 27001, NEN 7510 and the AVG. Where she mainly focuses on SMEs in the IT industry, healthcare organizations and non-profit organizations.
With a background in college law, in which she majored in ICT law, among other subjects, she combines legal knowledge with practical security expertise.
Walter Nap
Security Consultant
ISO 27001 Lead Auditor
Meet Walter
As a certified ISO 27001 Lead Auditor, Walter supports organizations in implementing, monitoring and maintaining the ISMS according to the ISO 27001 standard. He is also deployed as a Security Officer at several medium to large organizations.
With a Bachelor's degree in Econometrics & Operations Research and a Master's degree in Technology & Operations Management, he combines a keen analytical mind with practical operational experience.
Kirsten Wieringa
Security Consultant
Meet Kirsten
Kirsten started as a trainee at Nestor Security in 2025. While studying Integral Security Administration, she developed an interest in information security and privacy. This interest was further deepened during her internship at the ICT department of a hospital, where she worked with the CISO. There she researched how cyber exercises contribute to the resilience of healthcare institutions and helped set up a phishing campaign.
Within Nestor Security, Kirsten supports colleagues with internal audits, implementation of ISO 27001 and NEN 7510, and ISMS monitoring. Her goal is to further develop into an ISO 27001 Lead Auditor.