Three of the four cybersecurity leaders below started at their current employers in jobs that had little to do with security. One sold phone plans in a KPN store while finishing his degree. Another joined HEINEKEN as an IT auditor. A third spent years negotiating IT contracts and rolling out email systems for Randstad before he was given its security program. The fourth came to corporate security from diplomatic postings and cash logistics. Together they protect a national telecom network, a global technology company, one of the world’s largest brewers, and the world’s largest staffing firm.
Jeffrey Leusink-Nicolai – EVP & CISO, KPN
Jeffrey Leusink-Nicolai joined KPN in 2010 as a part-time customer sales and service advisor in a Groningen store, working alongside his bachelor’s and master’s studies. He was running stores as senior store manager while completing his MSc in Business Administration at the University of Groningen. From retail he moved into network and IT operations as an ITIL process manager, then into process, chain, and crisis communication management at KPN’s Service Quality Center. He directed innovation and support there and served as interim EVP of the center before becoming Vice President of the Chief Information Security Office in 2022. In March 2026 he was named Executive Vice President and CISO, responsible for KPN’s resilience strategy across cybersecurity, physical security, HR security, business continuity, and service reliability. He also chairs KPN’s Corporate Crisis Management Team and serves as vice-chair of the CISO Circle of Trust.
Gal Gnainsky – CSO, Philips
Gal Gnainsky began his security career as a regional security manager for a ministry of foreign affairs, posted in Warsaw and The Hague for eight years. He then spent more than four years directing global operations at I-SEC International Security in Amstelveen and nearly four as vice president of security services at Brink’s in Paris. After three and a half years as managing director of Wave-Sec, he led global security at Biogen. Gnainsky has been Chief Security Officer of Philips since January 2018, leading its corporate security group worldwide. His remit covers information security, product security, physical and personnel security, supply chain security, and crisis management.
Marina Marceta – CISO, HEINEKEN
Marina Marceta started as a consultant at Deloitte, spending more than four years there including a stint with Deloitte Croatia in Zagreb. She joined HEINEKEN’s global audit team in 2014 as a senior IT auditor and spent nearly four years reviewing the brewer’s technology controls. Her move into security came through a functional consultant role in the technology center of excellence, followed by three years in security incident management for Global Information Services. She then worked as product owner and later tribe lead for cyber defense and operations, leading those product teams globally. Marceta became HEINEKEN’s CISO in February 2025.
Martijn Nykerk – Global CISO, Randstad
Martijn Nykerk started as a systems engineer at Fisher-Rosemount and moved through IBM and AEGON Asset Management before joining Randstad’s I-bridge subsidiary in 2006. At Randstad Holding he set up the group’s global IT procurement function and managed license compliance audits. He also led the worldwide rollout of email archiving across more than 40 email systems, followed by the move to a single collaboration platform. His security role grew out of that work. He became IT compliance manager in 2016 and CISO of Randstad Digital Factory, the group’s shared infrastructure service center, in 2017. He was named Global CISO in March 2020, responsible for the information security program across all of Randstad’s operating companies. He has co-chaired Evanta’s Benelux CISO Governing Body since 2018.
Security Built on the Business
Three of these four learned their companies before they were asked to defend them. Leusink-Nicolai moved from a retail counter through operations and crisis management to the top of KPN’s security organization. Marceta audited HEINEKEN’s controls before she ran its cyber defense. Nykerk negotiated Randstad’s contracts and migrated its email before taking charge of its security. Gnainsky took the outside route, through diplomacy, cash logistics, and life sciences, and has now led Philips’ converged security function for nearly nine years. What the group shares is an understanding that security in large organizations is as much about operations, procurement, and crisis response as it is about technology.
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John Kevin Hao is a news and feature writer covering cybersecurity, technology, and business targeted for professional audiences.