A Practical Roadmap for Real and Lasting Cybersecurity Leadership.

When a new Chief Information Security Officer steps into the role, the first 100 days can define their legacy.
In The First 100 Days of the New CISO, seasoned cybersecurity leader and consultant JC Gaillard offers a pragmatic, experience-driven guide to succeeding in those crucial early months — and beyond.

Drawing on over two decades of advising major global organisations, Gaillard helps CISOs, executives, and boards understand what true leadership in cybersecurity looks like: calm, structured, and aligned with business priorities.
This is not another technical manual — it’s a leadership guide grounded in governance, culture, and the realities of corporate life.

This is more than a book about the first 100 days. It is a blueprint for the next decade of cybersecurity leadership.

- How to navigate the first 6 days, 6 weeks, and 6 months with clarity and composure.

- How to build trust and credibility across stakeholders before driving change.

- Proven techniques for aligning security with business strategy and governance.

- How to communicate effectively with boards and executive committees.

- Why culture, rhythm, and proportion matter more than tools or technology.

- What differentiates lasting transformation from short-term activity.

- Newly appointed CISOs seeking a structured, strategic start.

- Experienced security leaders looking to strengthen influence and impact.

- CEOs, CIOs, and board members who want to understand what effective security leadership looks like.

- Consultants and governance professionals focused on resilience, trust, and transformation.

Structured like a consulting playbook and written in clear, disciplined prose, this book offers the perspective and tools to turn uncertainty into direction — and direction into measurable impact. If you want to lead with confidence, build maturity, and leave a legacy that lasts beyond your tenure, The First 100 Days of the New CISO will show you how.