When Expertise Creates a Halo… Assumptions Follow!

During my last holiday I spent some time reading about cognitive biases again. Topics around decision-making and how we interpret competence.

One concept that caught my attention was the Halo effect.

The idea is simple: When someone is very good at one thing, we tend to assume they will also be good at other things. While reading about it, I realised I had once contributed to a situation where that assumption played a role.

When excellence creates a halo…

In many organisations something very predictable happens. Someone becomes recognised as an outstanding expert in a specific domain. Their knowledge is deep, their arguments convincing, their judgement reliable.

People start trusting their perspective. Gradually something else happens. The expertise begins to create a halo around the person.

If they are this good at their field, they will probably also be good at leading others. At least, that’s the assumption.

When leadership and expertise diverge

But expertise and leadership are not the same skill. Being right in a domain is different from creating an environment where others can grow in that domain.

Being able to win arguments is different from creating space for other perspectives. And being confident in your expertise does not automatically translate into helping others develop their own. Those differences are easy to overlook when someone’s expertise is very visible.

Assumptions

Looking back, I realise I also fell into another classic trap: assumptions.

I often joke about them using the old Benny Hill line: “When you assume, you make an ass out of u and me.”

Leadership decisions are no exception.  Sometimes the story we tell ourselves about someone’s potential is built more on assumptions than on evidence.

The uncomfortable part of leadership

Looking back, I also recognise something else. As leaders we sometimes keep believing in a path because we want it to work. We see potential. We invest time in coaching. We try to help someone grow into a role.

And sometimes that belief makes us protect someone longer than we probably should. Not because the person lacks talent. But because the role simply doesn’t match the type of talent they have.

When promotions move people away from their strengths.

Organisations often reward expertise with leadership roles. But doing so can sometimes move people away from the very thing that made them valuable in the first place.

An exceptional expert becomes an average or even a bad manager. Not because they are incapable. But because the skill set required is fundamentally different.

A leadership reflection

Looking back, the Halo effect helped me recognise a mistake I once made.

I assumed that excellence in one domain naturally translated into leadership potential. It doesn’t. Some people are brilliant experts. And sometimes the best way to respect that talent is not to move them away from it.

A question for leaders

Maybe the real leadership challenge is not recognising talent. Maybe it is recognising where that talent truly belongs. Before promoting someone, perhaps the real question should be:

Are we rewarding expertise… or are we unintentionally moving someone away from their greatest strength?

Another reflection inspired by reading about cognitive biases and how they influence leadership decisions.

The Cassandra Project

What Bushido Taught Me About Vulnerability in Leadership

For more than twenty years I have practiced Nihon Jiu Jitsu.
About ten years ago I earned my black belt, and today I hold a third degree black belt, which in most Nihon martial arts carries the title of Sensei.

Martial arts are often associated with strength, discipline and control.
Which is why Brené Brown’s work on vulnerability might seem unrelated at first glance.

Yet the more I reflected on both, the more I realised they point to the same leadership lesson.


Learning on the mat

After more than two decades of training, something slowly changes.

I am not as agile as I used to be.

When I was younger, speed and physical fitness compensated for many things. Today I rely more on timing, insight and a deeper understanding of the techniques. In some ways I am still improving. In other ways I am more aware of my limits.

The mat has a way of confronting you with reality.

When we teach students, we are very strict about the techniques we show. Everything we teach must work. In martial arts there is little room for theory that cannot be applied.

Experimentation happens mainly among the black belts. That is where techniques are explored, challenged and refined. It is also where assumptions can be tested and corrected.

Those moments can be uncomfortable.

But they are also where learning happens.


Bushido

Traditional Japanese martial arts are influenced by the philosophy of Bushido, the ethical code of the samurai.

Several virtues define it, but three resonate strongly with me.

Integrity means acting according to a clear ethical compass.
Respect means recognising the value of the person standing in front of you.
Loyalty means commitment to a shared purpose rather than individual gain.

These values shape behaviour in the dojo.

They also translate remarkably well to leadership.


Vulnerability

When I read Brené Brown’s book The Power of Vulnerability, one idea stayed with me.

Vulnerability is not weakness.

She describes vulnerability as uncertainty, risk and emotional exposure. Courage and vulnerability are closely connected.

The more I thought about it, the more familiar it felt.

Every time someone steps onto the mat they accept uncertainty.
Every time someone practices a technique they risk failure.
Every time someone allows themselves to be corrected they expose their weaknesses.

Improvement requires vulnerability.


A leadership moment

I was reminded of that lesson during a difficult leadership decision.

We were working on an important initiative and significant resources had already been invested. The expectation was clear. The organisation wanted progress and results.

But the deeper we went, the clearer it became that the foundation was not strong enough. Continuing along the same path would only create larger problems later.

The responsible decision was obvious. The easy decision was something else entirely.

In the end I pushed for what could best be described as a complete reset, a tabula rasa. It meant accepting that the timeline would move much further out than anyone wanted to hear.

You can imagine that this was not a popular message. But leadership sometimes requires choosing the uncomfortable truth over the convenient illusion.


Strength and vulnerability

Martial arts are often associated with toughness.
Leadership is often associated with confidence.

But both disciplines share the same underlying truth.

Strength without vulnerability easily becomes arrogance.
Vulnerability without strength becomes hesitation.

True leadership requires both.

After more than twenty years on the mat, one lesson keeps returning.

The moment you believe you have nothing left to learn is the moment you stop improving.

Bushido and modern leadership thinking meet in that exact place.

Both remind us that courage is not about appearing invulnerable.
It is about having the strength to face reality and adjust when necessary. Even when that reality is uncomfortable.

In the dojo we bow before stepping onto the mat.
Not just out of tradition, but as a reminder that learning requires humility.

Leadership might benefit from the same mindset.

The Cassandra Project

When the Same Idea Sounds Better from the Outside

During my last holiday I once again found myself reading about cognitive biases and decision-making.

At this point I’m starting to suspect that my holiday reading is slowly turning into blog material.

One concept that caught my attention this time was the messenger effect. The idea is simple: People often judge information not only on its content, but also on who delivers it.

And while reading about it, I realised I had seen a particular version of this dynamic more than once in organisations. Almost like a reversed version of the Not-Invented-Here syndrome.

When ideas sound different depending on who says them

Most organisations know the classic Not-Invented-Here syndrome. Ideas coming from outside are rejected because they were not invented internally.

But sometimes the opposite happens. An idea proposed by someone inside the organisation is questioned, analysed, and debated. Until eventually an external consultant arrives. The consultant explains the situation, proposes a direction… and the room suddenly agrees.

The interesting part is that the advice often sounds very familiar. Because someone inside the organisation had already said something very similar. A moment I’ve seen more than once.

I remember a meeting where exactly that happened. An internal colleague had been raising a certain idea for some time. The arguments were solid, but the discussion kept circling around doubts and alternative interpretations.

Then later an external consultant was asked to review the situation.

After analysing the problem, the consultant explained the recommended direction. People in the room nodded.

“That makes sense.”

The internal colleague looked surprised. And perhaps a little frustrated. The idea had not really changed. Only the messenger had.

The messenger effect

Looking back, this dynamic is a clear example of the messenger effect. The credibility of an idea is sometimes influenced less by the argument itself, and more by who presents it. External consultants are often perceived as neutral experts. Internal colleagues are sometimes seen as part of the system that created the problem.

Even if the internal person understands the context far better.

A leadership reflection

This observation left me with an uncomfortable reflection. Sometimes organisations do not need new ideas. They need the same idea delivered by a different messenger. And sometimes the real issue is not the idea itself, but how it is communicated.

That raises a leadership question. Are we listening carefully enough to the expertise that already exists inside the organisation? And are we giving our people the tools, support and trust they need to make their ideas heard?

A question for leaders

Maybe the real leadership challenge is not finding the best ideas. Maybe it is recognising them when they already exist within the organisation. Because sometimes the difference between a rejected idea and an accepted one is surprisingly small.

It is simply who says it.

And the real question becomes:

Are we listening to the best ideas… or simply to the most credible messenger?

Another reflection inspired by reading about cognitive biases and how they influence leadership decisions.

The Cassandra Project

When knowledge meets confidence

During my last holiday I had the time to catch up on some reading that had been sitting on my list for a while.

Topics around decision making, cognitive biases and how we form opinions.

One concept that was interesting: The Dunning–Kruger effect.

At the time it felt like an interesting theory about how people sometimes misjudge their own competence.

Two weeks ago, I recognised it in my personal surroundings. A discussion started about a specialised topic. Someone present had real professional expertise in the matter. The kind of expertise that comes from years of working in this particular field.

The conversation shifted and ‘certainty’ entered the room. Something struck me. The person with the deepest expertise spoke with nuance and caution, while the other one spoke with increasing certainty. Experience was careful and confidence was loud. And suddenly that concept I had been reading about months earlier came back to mind. Not as theory,… but in reality.

When expertise stops speaking.

The Dunning–Kruger effect is often used to explain why people with little knowledge can feel very certain about their opinions. But what interests me more is the other side of that dynamic.

Experts tend to be more cautious because they are more aware of the complexity of the topic.

And this tends to lose the room. In many discussions whether in society, organisations or families, the most confident voice often wins, not the most informed one.

And over time something else starts to happen… The people who actually understand the topic sometimes stop engaging altogether. And not because they lack arguments.

The leadership mirror.

That moment also triggered a more uncomfortable reflection for me.

Throughout my career I’ve been (most of the time) fortunate to work with leaders and colleagues who never relied on hierarchy to win arguments.

People who took the time to listen. People who encouraged debate. I realise how valuable such environment is.

Because the real danger in organisations is not that someone overestimates their knowledge.

The real danger is when the people who know more stop speaking up. That’s when mistakes go unchallenged. That’s when confidence starts replacing competence.

Which leads to a question I sometimes ask myself in my role as a leader.

Do the people around me feel comfortable challenging ideas, including mine?

Does hierarchy silently shape the conversation?

It’s easy to say we value open discussion. It’s much harder to build an environment where people genuinely feel safe enough to disagree. Maybe this is one of the hardest leadership challenges.

The Dunning–Kruger effect isn’t just a psychological curiosity. It’s a reminder of something leaders should never forget: Confidence and competence are not the same thing. And good leadership isn’t about always having the right answers.

It’s about creating an environment where the best understanding can surface, even when it contradicts the person with the most authority.

Because when expertise stops speaking up, the problem isn’t psychology anymore.

It’s leadership.

Maybe It’s Not Imposter Syndrome … Maybe It’s Just Leadership …

Recently I caught myself wondering something uncomfortable.

Am I actually performing at the level I expect from myself?
From the outside, things look fine. Projects move forward, decisions get made, responsibilities grow.
Yet occasionally there’s a quiet doubt: How high of a performer am I… or have I simply been fortunate with timing, opportunities, and the people around me?

A while ago I would probably have called that feeling imposter syndrome.
Today I’m not so sure anymore.

The illusion of certainty

Once you spend enough time in leadership environments, a few things become obvious.

First: Nobody has the full picture.
Second: Most important decisions are made with incomplete information.
And third: Confidence is often performative.

Many leaders project certainty long before they actually feel it internally.

At some point you realize something slightly uncomfortable: Most people are not executing a perfectly defined plan.
They are navigating complexity in real time.

That realization can be strangely liberating, but also humbling.

Vulnerability and leadership

In The Power of Vulnerability, Brené Brown describes vulnerability not as weakness, but as the courage to show up without guarantees.

That definition resonates strongly with leadership.

Because leadership rarely comes with guarantees.

You make decisions without having all the answers.
You move forward without knowing the full outcome.
And occasionally you wonder whether you’re really doing as well as people around you might assume.

Admitting that uncertainty can feel uncomfortable, especially in environments where leaders are expected to project confidence.
But pretending certainty where it doesn’t exist isn’t leadership either.
The trap high performers fall into….

Something else I’ve noticed over time.
Many high-performing professionals have a tendency to internalize outcomes too quickly.
When something goes wrong, the instinctive reaction is often:

“Where did I misjudge this?”

That instinct comes from ownership. And ownership is a good thing.
But it can also create a misleading equation:

Outcome = my judgment

Reality is more complicated.

Outcomes are shaped by systems: strategy, execution, people, timing, market conditions, and sometimes plain randomness.
Your judgment is only one variable in that equation.
Recognizing that doesn’t remove responsibility.
But it does create a more honest perspective on causality.

Decision quality vs. outcome quality

One mental shift that has helped me is separating decision quality from outcome quality.
A good decision can still produce a bad outcome if circumstances change.
A poor decision can occasionally work because of luck.

If we evaluate ourselves purely on results, we risk learning the wrong lessons.

A better question is:

Was the reasoning sound given the information available?
Did we execute well?
What changed externally?

Only after that does it make sense to question your own judgment.

Why leadership discussions often drift.

Another observation: Many meetings quickly drift toward operational details.

Which tool should we use?
Who owns the task?
What timeline should we set?

But those questions sometimes appear before the real problem has been clearly defined.
Organizations naturally gravitate toward action. Action feels productive.

Yet leadership often requires something different: stepping back and clarifying the problem first.

Sometimes the most valuable contribution in a meeting is simply asking:

What problem are we actually solving?
What outcome are we trying to achieve?
Is this even the right initiative?

These questions may sound simple, but they often change the entire direction of the discussion.

The uncomfortable transition

Looking back, I think many professionals move through three phases in their career.

Performer
“I must prove I’m capable.”

Expert
“I must know more than others.”

Leader
“I must make decisions when nobody knows.”

The transition from expert to leader is not always comfortable.
Expertise gives certainty. Leadership often removes it.
And perhaps that’s where the feeling people call “imposter syndrome” sometimes appears.

Not because someone is incapable, but because the job itself has changed.

A more honest question

The more I reflect on it, the more I think the real challenge of leadership is not eliminating uncertainty.
It’s learning to operate with uncertainty.

For me, the question has gradually shifted, even though I often struggle…

Instead of asking:

“Am I good enough for this?”

A more useful question might be:

“Given what we know today, what is the best decision we can make now?”

And maybe the real question for many of us is this:

Is what we call imposter syndrome actually just the feeling of stepping into responsibility that is bigger than certainty?

A reflection, part of The Cassandra Project

Strength Does Not Need Volume

In every professional environment, noise eventually emerges.
Doubt. Interpretation. Narratives that travel faster than facts.


It is not an exception. It is a constant.


Those who carry responsibility become visible.
And visibility invites projection.


Success is rarely judged on substance alone. It is filtered through perception.
That is not criticism. It is human nature.
In those moments, something fundamental becomes clear:


The difference between words and work.
Words can simulate weight.
Work carries real weight.


What is built on discipline, consistency, and measurable contribution
does not require defense.
It reveals itself over time.,.. in results, in continuity, in earned trust.


Leadership therefore asks something simple, though not easy:
Not to react to every signal,
But to keep building what endures.


Not everything loud is strong.
Not everything quiet is weak.


And between the two lies the difference
between noise
and strength.

Arcade Games

I’ve always believed that the best way to learn is to dive in. I had never used a circular saw, designed a piece of furniture, or built an arcade machine — but I decided to take on the challenge.

When the original blueprints proved inaccurate, I started from scratch, adapting the design step by step. It became an exercise in curiosity, creative problem-solving, and learning entirely new skills from the ground up.

Generative AI to create a realistic picture

Probably have seen this on Facebook. Here is the prompt:

Create a vertical 9:16 hyper-realistic bust portrait of a man (referencing attached image) reimagined as a fusion between human and T-1000 Terminator. The bust is showcased inside a premium transparent acrylic display case with a brushed gunmetal frame. Half of his face and upper torso are human, with realistic skin texture, classic Terminator facial scars, a rugged jawline, and a piercing gaze. The other half transitions into polished, mercury-like liquid metal with flowing chrome skeletal structures, glowing blue LED eye, exposed circuitry, and biomechanical musculature beneath translucent synthetic skin.

He wears a futuristic, battle-damaged leather jacket and a metallic-textured undershirt torn to reveal integrated machine components. Lighting inside the case is cinematic: cool bluish tones casting dramatic shadows and metallic reflections. The base is a glossy pedestal etched with “TERMINATOR serif typography. The scene is set within a sleek, minimalist designer studio—white desk, soft shadows, and high-end ambient daylight, evoking an ultra-premium film memorabilia exhibit from a dystopian future.”

The Hundred-Page Machine Learning Book

(2019-05-30)

A must read for ICT Managers to keep up with the latest trends. Even though you might have studied it at University. For me it has been a while…

Today’s top companies undergo the most significant transformation since industrialization. Artificial Intelligence disrupts industries, the way we work, think, interact. Gartner predicts that by 2020 AI will create 2.3 million jobs, while eliminating 1.8 million. Machine Learning is what drives AI. Experts in this domain are rare, employers fight for the ML-skilled talent. With this book, you will learn how Machine Learning works. A hundred pages from now, you will be ready to build complex AI systems, pass an interview or start your own business.

All you need to know about Machine Learning in a hundred pages

Supervised and unsupervised learning, support vector machines, neural networks, ensemble methods, gradient descent, cluster analysis and dimensionality reduction, autoencoders and transfer learning, feature engineering and hyperparameter tuning! Math, intuition, illustrations, all in just a hundred pages!

Power of Vulnerability

(2018-09-30)

Have read the book. Very interesting to read and learned new ways to do stakeholder management, knowing what is the ‘normal’, understanding ‘fault & shame’..

This is really a ‘must read’

Is vulnerability the same as weakness? ”In our culture,” teaches Dr. Brené Brown, ”we associate vulnerability with emotions we want to avoid such as fear, shame, and uncertainty. Yet we too often lose sight of the fact that vulnerability is also the birthplace of joy, belonging, creativity, authenticity, and love.” On The Power of Vulnerability, Dr. Brown offers an invitation and a promise-that when we dare to drop the armor that protects us from feeling vulnerable, we open ourselves to the experiences that bring purpose and meaning to our lives. Here she dispels the cultural myth that vulnerability is weakness and reveals that it is, in truth, our most accurate measure of courage. 

IMES DEXIS celebrating 50 years

IMES DEXIS celebrated their 50 years of business and asked for some testimonials.

Why it’s so nice to work here

Please don’t mind the strange face I’m making. This is only the way I look for half of the day, the other part I’m sleeping…

ELK Stack & Business Architecture Performance Metrics

(2017-08-30)

My teams just finished up a proof of concept using ELK stack, proving trends and safeguarding business by exposing inefficiencies in mission critical environment and fixing it.

There is now pro active alerting when systems tend to fall or go in a diminished performance state before they actually do. Better alerting than standard server/services monitoring !

Big data analyses at its’ best.

Next step is creating a cluster for robust and intense computations…

If you’re working in a DevOps env. focus on business metrics is key. However, you want to derive those metrics and the data to support your meeting those key performance indicators using tools that support effective collaboration with a minimum of misery.

(2017-10-30)

Full blown ELK stack cluster implementation ready and in production

If you want to read more: https://www.elastic.co/what-is/elk-stack

How to win friends and influence them

(2017-09-30)

This book really helped me in my current function/job. A great tool to understand people, what drives them, and how to interact with those that don’t see your point of view immediately

The most famous confidence-boosting book ever published; with sales of over 16 million copies worldwide!

Millions of people around the world have improved their lives based on the teachings of Dale Carnegie. In How to Win Friends and Influence People, he offers practical advice and techniques, in his exuberant and conversational style, for how to get out of a mental rut and make life more rewarding. 

His advice has stood the test of time and will teach you how to: 
– Make friends quickly and easily
– Increase your popularity
– Persuade people to follow your way of thinking
– Enable you to win new clients and customers
– Become a better speaker 
– Boost enthusiasm among your colleagues

This classic book will turn your relationships around and improve your interactions with everyone in your life.

Hybrid active/active VMWare data center with Huawei Network Systems

(2014/04/15)

Back in 2013, Huawei was not as well known in the SMB business as it is today. They really needed to get a foothold in the Benelux on that level. I was in need of a new local, small sized but performing data center. Huawei delivered a ‘no cure, no pay’ solution to handle traffic between the data nodes and the edge switches and the clients

Here is the case study:

An excerpt:

Brute Force Attack demonstrated

When I worked at a hospital, back in 2009 , I had trouble to introduce a basic security mindset with co-workers throughout the organization.

The term ‘think before you click’ and ‘safeguard your passwords’ was introduced, together with this video.

Here I devised a simple (single threaded) program on how to beat the Facebooks app Word Challenge.

When people looked at it, and when I showed them the firewall logs on how much we were targetted for hacking, an awareness was born.