Governing Body Spotlight

Olivier Tillier is the CISO at Bouygues Construction, leading cybersecurity across France, Morocco, and Vietnam within a global organization of 35,000+ employees in over 60 countries. He brings 25+ years of leadership in defense, telecom, and consulting—aligning cyber strategy with business impact.

Learn more about the France CISO community here.
 

Give us a brief overview of the path that led to your current role.

My journey began in the French Armed Forces, where I spent over 25 years in operational command, strategic influence, and crisis leadership roles across multiple international missions. 

I transitioned into the civilian sector through leadership in training and transformation at Saint-Cyr Formation Continue, followed by consulting in HR and organizational development at CEPIG. I then led large-scale infrastructure projects at Axione before joining Bouygues Construction in 2023 as Chief Information Security Officer. Today, I lead a global cybersecurity team across three continents, aligning security strategy with business resilience in a group of over 35,000 employees in 60+ countries.
 

What is one of your guiding leadership principles?

"Taking care of people while driving performance, with clarity, trust, and collective alignment."

This principle is reflected in my focus on team cohesion, crisis management, and my ability to bring diverse groups together around a shared mission.
 

What is the greatest challenge CISOs face today, and how are you addressing it?

One of the greatest challenges facing C-level security leaders today is balancing cybersecurity resilience with business agility—especially in large, decentralized, and international organizations like Bouygues Construction.

As CISO, I address this by:

• Embedding security into business strategy: I work closely with executive leadership to ensure that cybersecurity is not a constraint but a lever for performance and trust.
• Leading a globally distributed team: I coordinate 52 cybersecurity professionals across France, Morocco, and Vietnam, ensuring alignment despite geographic and cultural diversity.
• Driving risk-based decision-making: I’ve implemented a structured cyber risk mapping and defense planning process to prioritize actions that reduce exposure while supporting operational continuity.
• Responding with speed and clarity: I lead crisis coordination and incident response with a focus on decisiveness and communication, especially in high-stakes situations.
   

What is the key to success for someone just starting out as a CISO?

For someone just stepping into a CISO role—especially in a large, international organization like Bouygues Construction—the key to success lies in this principle: “Earn trust early, align security with business goals, and lead with clarity in complexity.”

In my case,  my success has been built on:

• Building credibility quickly with executive leadership and operational teams.
• Translating cybersecurity into business value, not just compliance or technical defense.
• Leading globally distributed teams with a shared vision and strong coordination across France, Morocco, and Vietnam.
• Responding decisively in crisis, while maintaining a long-term strategic roadmap.
   

How do you measure success as a leader?

As a leader, I measure success by the impact I create through others—not just in terms of results, but in how people grow, collaborate, and respond under pressure.

In my case, success is reflected in:

• Team alignment and resilience: Leading 52 cybersecurity professionals across three continents requires clarity, trust, and shared purpose.
• Crisis readiness and calm execution: Your ability to coordinate high-stakes security incidents while maintaining strategic focus is a key marker of leadership maturity.
• Business integration: You ensure that cybersecurity is not siloed but embedded in Bouygues Construction’s broader operational and strategic goals.
• Legacy of leadership: From military command to corporate transformation, your path shows that success is also about leaving behind stronger, more autonomous teams.
   

What is the value of being a member of Gartner C-level Communities?

As CISO of Bouygues Construction, I lead cybersecurity across a global organization of 35,000+ employees in over 60 countries. Being part of this community allows me to:

• Benchmark practices and gain insights from other leaders navigating digital transformation, resilience, and risk.
• Challenge my thinking through curated discussions and shared experiences.
• Contribute meaningfully by sharing lessons learned from crisis leadership, global coordination, and aligning security with business impact.
   

Gartner C-level Communities Governing Body members share their insights and leadership perspectives to shape the agendas and topics that address the top priorities impacting business leaders today.
 

By CISOs, For CISOs®

Join the conversation with peers in your local CISO community.