In 2014, Santiago enrolled in an MBA at INSEAD, expecting to deepen his understanding of business. What he discovered was a great deal more about himself. That is something I recognise about the INSEAD experience: it has a way of challenging your expectations and leaving you with much more than an education.

Being surrounded by people from different countries, cultures and professional backgrounds also changed his perspective. He began to understand the importance of recognising his own strengths and surrounding himself with people whose capabilities complemented his. It was an experience that would later prove fundamental to the way he built ChangeNOW with his co-founders, Rose-May and Kevin.

During that period, his definition of success began to change. Having grown up associating financial achievement with personal worth, he realised that money alone was no longer a sufficient objective. He wanted to create something he could be proud of, using his entrepreneurial skills to build a business that would also have a positive impact on the planet.

While at INSEAD, he founded TEDxINSEAD, an experience that brought him into contact with entrepreneurs and changemakers including Boyan Slat, founder of The Ocean Cleanup, and Joséphine Goube, a social entrepreneur and advocate for refugees. He was struck by the talent and quality of the people working on environmental and social challenges, but also by how little access many of them had to funding, visibility and the networks that could help their ideas grow.

It was during this time that the thinking behind ChangeNOW began to take shape.

Building an Ecosystem for Change

As Santiago takes me through the evolution of his thinking, he refers to the theory of change and the importance of understanding how major transformations happen.

"If we look back in history, the big changes and movements never came through an individual, but always through an ecosystem of people. The Renaissance did not happen in isolation."

His conviction was that there were already remarkable people developing solutions to some of the world's most pressing challenges, but they were often operating in separate environments, without the connections or resources required to scale their work. What was needed was an ecosystem capable of bringing them together with investors, businesses, policymakers and others who could help turn promising ideas into broader change.

Santiago was also interested in the forces that make transformation possible. He had observed that change often creates resistance, particularly when people feel that what they know or value is being threatened. One of his ideas was to bring some of the familiar mechanisms of the business world into the impact space, creating an environment where entrepreneurs could access capital, develop partnerships and grow their organisations without having to operate entirely outside established economic structures.

ChangeNOW was conceived with the ambition to bring the people developing solutions into contact with those who had the resources and influence to help them succeed.

The first edition was planned for 2017 at Station F in Paris. A few months before the event, Santiago and his co-founders had secured the venue and the speakers, but they still had no funding. Santiago had invested his own money to secure the location and had just become a father for the first time.

As he recalls that period, Santiago puts his hands over his face. It is the only moment during our conversation when I can sense how vividly he remembers the pressure of those months.

I ask whether he ever considered giving up, particularly when the financial uncertainty was so great.

"No, giving up was never an option."

I find myself thinking about what makes some entrepreneurs continue when others might decide to change direction. In Santiago's case, there was an extraordinary conviction in what he was trying to build, but also the support of his partner in life and business, who helped him through the most difficult moments.

The timing of the first edition also coincided with a growing mobilisation around climate change in France and Europe, following the United States' announcement that it would withdraw from the Paris Agreement. The funding eventually arrived, and ChangeNOW was able to launch.

Santiago refers to The Alchemist by Paulo Coelho when describing that experience, a book that explores what happens when someone commits to pursuing a deeply held ambition. I can understand why the story resonates with him, particularly after hearing how close the first edition came to taking place without the financial resources needed to make it happen.

Knowing Where You Are Going

I am curious to understand what drives someone who has already built an organisation of this scale, and Santiago's answer takes us back to the personal questions that first led him away from banking.

"I want to feel that my existence means something, and two things give me that feeling: creating and loving."

Creating has clearly remained an important part of his life, although the meaning of what he wants to create has evolved considerably. Through ChangeNOW, he has built an international community that connects people working on environmental and social solutions, while extending the organisation's influence into education and public debate.

Among its initiatives is the French Grandes Écoles Ranking, which assesses how higher education institutions are addressing ecological and social transition and aims to encourage changes in the way future leaders are educated. ChangeNOW has also helped bring ecological transition into political debate, creating opportunities for the subject to be discussed beyond the communities traditionally engaged with sustainability.

Throughout this journey, Santiago has relied on what he calls his "North Star", a clear understanding of the objective he is working towards.

"You need to know where you are going. Of course there will be a lot of noise along the way, and it's OK to adjust your direction, but the goal needs to be clear."

His relationship with success has changed just as much as his professional life. If he could give his younger self one piece of advice, it would be that the money you earn does not determine your value. As a young man, financial success was a way of proving his worth, whereas today he is more interested in whether his work is making a positive difference.

He approaches this in a surprisingly concrete way, keeping a diary in which he records examples of the impact he and his organisation have created.

Turning Different Perspectives Into Innovation

There is another aspect of Santiago's thinking that I find particularly interesting. When he shares a new idea, he knows that some people will immediately understand what he is trying to achieve, while others may struggle to see its potential.

Rather than being discouraged by those who do not immediately agree, he is interested in the distance between his own vision and their perspective. Understanding what prevents someone from embracing an idea, and finding a way to connect their thinking with his, can open up possibilities that might not have emerged among people who already share the same assumptions.

It is a perspective that connects naturally with his original ambition for ChangeNOW. Bringing together entrepreneurs, investors, businesses and policymakers means working with people who have different priorities, incentives and ways of understanding the world. The opportunity for innovation often comes from creating connections between those perspectives and finding solutions that can work across them.

The Next Ten Years of ChangeNOW

Almost a decade after its first edition, ChangeNOW is entering another entrepreneurial chapter. What began as an event in Paris has developed into an international ecosystem, bringing together changemakers from more than 140 countries and a community of over 1,400 investors.

Santiago is now thinking about how to take that ecosystem further.

"We want to share ChangeNOW with communities around the world, and turn it into a movement."

The organisation has begun developing ChangeNOW Hubs, with pilot initiatives planned in Turkey, Bangalore and Tunisia. The ambition is to allow communities to create their own connections, partnerships and opportunities for impact, extending the original idea beyond the annual summit in Paris.

In many ways, this next chapter reflects what inspired Santiago to create ChangeNOW in the first place: positive impact happens when people come together.