2026-04-16 –, Merck Plenary (Spectrum) [1st Floor]
Open source powers the world's digital infrastructure — from AI research to enterprise data pipelines. But how do you build a sustainable business on it? This panel brings together three figures from the heart of the global open source ecosystem: Yann Lechelle (Probabl), who made the deliberate switch from infrastructure CEO to open source; Sylvain Corlay (QuantStack), whose consulting business is built from and around the core of the Jupyter ecosystem and its maintainers; and Ines Montani (Explosion / spaCy), one of the most influential voices in NLP tooling. Three founders. Three paths. Real answers on what it takes to build — or switch to building — a business in open source.
The discussion centres on concrete experience — different starting points, different ecosystems, different business models — with the shared thread being open source as a deliberate professional and commercial choice.
Key Questions:
Different entry points: You each came to building a business on open source from a different direction. What drove that decision — and what did you not expect?
Where the business actually starts: Open source is the foundation, not the product. How do you define what you sell, and to whom?
Community and commerce: How do you maintain trust and credibility in an open source community while running a commercial operation around it?
Open source and AI: The AI landscape is consolidating fast around closed systems. What does that mean for open source projects and the businesses built on them?
European perspective: Is there something specifically European about the way you think about open source as a business — around sustainability, sovereignty, or independence?
Advice: What would you tell someone who wants to build a business on open source — or switch to doing so — and has not yet started?
Over the past three decades, from Paris to Los Angeles, via Cambridge, UK, and New York, and back again, he has leveraged software to unlock business potential across a wide range of fields: financial markets through real-time trading platforms; cartoon animation through centralized asset management tools; yield management through behavioral analytics and social networks; digital art in new media; mobile app discovery through recommendation engines; mobile app monetization through innovative ad formats; and applied AI to deploy state-of-the-art voice recognition on the edge.
More recently, over the past three years, he developed Scaleway, a below-the-radar cloud company, into a credible regional alternative to the three major hyperscalers. During that time, he grew the team threefold to 600 employees while leading complex change management.
He is now the co-founding Executive President and Chairman of Probabl, the scikit-learn company on a mission.
As an entrepreneur, he has founded, co-founded, or joined a number of startups, developing products that have reached hundreds of millions of end users globally, often through elegant user interface design and innovative user experiences. As a key shareholder, he has also contributed to the growth and exit of several companies.
As an advisor, board member, and angel investor, he now tracks the progress of many more forward-looking ventures.
In Paris, he is a strong advocate for the tech ecosystem: a co-founding member of France Digitale and HUB AI Paris, as well as Entrepreneur-in-Residence at INSEAD Business School.
Ines Montani is a developer specializing in tools for AI and NLP technology. She’s the co-founder and CEO of Explosion and a core developer of spaCy, a popular open-source library for Natural Language Processing in Python, and Prodigy, a modern annotation tool for creating training data for machine learning models.
Sylvain Corlay is the founder and CEO of QuantStack.
As an open-source developer, Sylvain is active in the scientific computing ecosystem, particularly within the Jupyter project, as well as the conda-forge and xtensor projects. In 2018, he and the other Jupyter leadership members were awarded the ACM Software System Award.
Beyond QuantStack, Sylvain is involved in the community. He served as a board member of the NumFOCUS Foundation from 2018 to 2024, as the vice-chair of JupyterCon 2020, and General Chair of JupyterCon 2023 in Paris. He has coordinated the PyData Paris community since 2017, both as the organizer of the meetup group and as co-organizer of the annual conference in 2024 and 2025.
Alexander C.S. Hendorf is an independent AI and open-source strategy advisor working with companies in regulated industries. With 20+ years of hands-on experience across 50+ technologies — from the Python ecosystem to vector databases — he bridges the gap between boardroom decisions and technical execution. Alexander is a Python Software Foundation Fellow, heads the Open Source Working Group of the KI Bundesverband, serves on the board of the Python Software Verband, and has delivered 100+ talks in 15+ countries.