What you do in your first 100 days as a leader can shape everything that follows.
And yet, this is exactly where many capable leaders lose ground—not because they lack expertise, but because they misread what the moment actually requires.
In my recent conversation with JC Gaillard, author of The First 100 Days of the New CISO, we explored why this critical window is so often mishandled. Although his work sits in the cybersecurity space, the patterns he describes are universal. This is not a technical conversation. It’s a leadership one.
At the centre of it is a simple but uncomfortable truth: most leaders think their first 100 days are about proving themselves. In reality, they are about understanding where they’ve arrived.
Why Leaders Get the First 100 Days Wrong
There’s a strong pull, particularly at senior levels, to demonstrate value quickly. New leaders often feel an unspoken pressure to act—to make visible progress, deliver early wins, and show they were the right appointment.
On the surface, that makes sense. But it rests on a flawed assumption: that action builds credibility.
What Gaillard challenges is the sequencing of that thinking. The issue isn’t whether leaders should act. It’s when.
When leaders move too quickly, they bypass the one thing that determines whether their actions will land well or fail quietly. Context. Every organisation carries its own history, its own internal tensions, and its own version of what has and hasn’t worked before. Without understanding that, even well-intentioned decisions can miss the mark.
This is where many leaders go wrong. They bring solutions that worked elsewhere, only to discover, often too late, that the environment they’ve entered operates by a different set of rules.
Credibility Doesn’t Come From Action
One of the strongest ideas in the conversation is that credibility must come before change.
And credibility, in this context, isn’t built through decisive action or technical expertise. It’s built through how a leader shows up in those early weeks.
What stands out is the emphasis on listening – not as a leadership cliché, but as a disciplined practice. Not surface-level engagement, but deep listening that uncovers what stakeholders actually need, where the friction points are, and how the organisation really functions beneath its formal structures.
There’s a question Gaillard returns to repeatedly: How can I help you?
It sounds simple, but it shifts the dynamic. It moves the leader from being someone who arrives with answers to someone who is willing to understand before responding. Over time, that shift changes how others engage with them. The work stops being “their agenda” and starts becoming something shared.
That’s the point where credibility begins to take hold.
The Reality Beneath the Org Chart
Another thread running through the discussion is the gap between how organisations appear and how they actually operate.
On paper, structures are clear. Roles are defined. Decision-making looks logical.
In practice, influence is rarely that straightforward.
Power tends to sit in informal networks. Decisions are shaped by relationships, history, and competing priorities. Some parts of the organisation move quickly, others resist change, and not always for obvious reasons.
Leaders who take the time to understand this layer early on are far more effective. Not because they are playing politics, but because they are no longer operating blind to it.
For those who ignore it, progress can feel slower, more frustrating, and often inexplicably blocked.
A Different Way to Think About the First 100 Days
To bring structure to this period, Gaillard describes a rhythm rather than a checklist: six days, six weeks, six months.
The early days are about mapping the landscape – getting a sense of the organisation, its priorities, and its pressure points. The following weeks shift toward engagement, where leaders begin shaping direction alongside stakeholders rather than in isolation. By the time they reach the later stage, the focus turns to building the systems and structures that allow that direction to be executed.
What’s notable about this approach is what it deprioritises. It doesn’t rush leaders toward action. Instead, it creates space for understanding to come first, so that when action does happen, it’s grounded and more likely to succeed.
Why Simplicity Signals Strength
There’s also a subtle but important point about how leaders communicate early on.
It’s tempting to demonstrate depth through detail. To present comprehensive strategies, detailed plans, and highly structured roadmaps. But in the early stages, this can have the opposite effect.
Overly complex thinking often creates distance rather than alignment. It signals certainty before understanding has been established.
By contrast, clarity and simplicity tend to build confidence. When leaders can articulate direction in a way that others recognise and relate to, it becomes easier for people to engage with it and eventually, to take ownership of it.
That ownership is what turns a strategy into something that actually moves.
Authority Is Earned, Not Declared
Perhaps the most understated insight from the conversation is how authority is established.
In many organisations, there’s an assumption that authority comes with the role. That once appointed, a leader has the mandate to act.
In reality, authority is something that is earned in the system itself. It grows through trust, through consistency, and through the way a leader navigates the complexity around them.
In the first 100 days, that process is already underway—whether the leader is conscious of it or not.
What Becomes Possible When It’s Done Well
When leaders approach this period with the right mindset, something shifts.
They are no longer seen as new or external. They become part of the leadership fabric of the organisation. Their voice carries weight not because of their title, but because of the trust they’ve built.
From there, their influence expands. They are invited into broader conversations. They contribute to shaping direction, not just executing it.
Without that foundation, many leaders find themselves stuck in delivery – valued, but not truly influential.
Final Thought
The first 100 days as a leader are often treated as a proving ground.
But they’re not.
They are a positioning period—one that determines how a leader will be seen, how they will be heard, and how much influence they will ultimately have.
And the leaders who navigate it well tend to do something deceptively simple.
They slow down.
They listen.
And they earn the right to lead before trying to prove that they can.
🎥 Watch the Full Interview
Buy the book here.
About JC Gaillard
JC Gaillard is the Founder and CEO of Corix Partners, a UK-based Boutique Management Consultancy Firm and Thought-Leadership Platform, focused on assisting CIOs and other C-level executives in resolving Cyber Security Strategy, Organisation and Governance challenges.
About Ros Cardinal:
Rosalind Cardinal is a leadership strategist, author, and founder of Shaping Change, an award-winning consultancy helping leaders and organisations build cultures where people and performance thrive. With a background in organisational development and neuroscience-based coaching, Ros works with boards, executives, and teams to create lasting change through clarity, courage, and connection.
Book a chat with Ros.
Read Next: The Influence Equation – Why Good Work Stops Being Enough