Stéphane Gilbert

Stéphane Gilbert did not come to software from software. He is a water-treatment engineer who graduated from the engineering school in Limoges in 2001, then spent the better part of two decades managing water inside industry, including a stretch as a water-resources and quality manager for the bottled-water side of Nestlé Waters. That is an unusual background for a tech founder, and it is the whole point of Aquassay: the people who built it knew water first, and reached for data second.

Stéphane Gilbert founded Aquassay in Limoges in 2015 with Jean-Emmanuel Gilbert, a chemistry PhD, as the data-driven successor to an earlier engineering firm he ran called Proj&Eau. The earlier company did the same job by hand, sending engineers to measure and diagnose how a factory used water. Aquassay took that same expertise and wired it into a cloud platform, because, as Stéphane puts it, water in a factory is everywhere: it is used to wash, rinse, dilute, dissolve, heat and cool, and to understand any of it you first have to see the whole cycle, from the well to the wastewater plant.

Stéphane Gilbert's core idea is that the water in a factory is a hidden world. It runs inside pipes where nobody watches it, so leaks, scaling, corrosion and quality problems quietly eat into production and revenue before anyone notices. Aquassay's e-Water Efficiency platform plugs into a plant's meters and sensors and turns that invisible flow into live dashboards and alerts, which he compares to getting a new pair of glasses. The first three months of simply being able to see the water, he says, already kill the spillage and the bad automation nobody knew was there.

Stéphane Gilbert likes to keep the value concrete rather than abstract, and his favourite example is a reverse-osmosis story, reverse osmosis being the membrane process factories use to purify water. One client's purification skids lost half an hour of bad-quality water every time they restarted, until Aquassay's data traced it to a design flaw; a single extra valve, found by watching the data, divided that downtime by fifteen. That is the pitch in one number: the savings are an operating-cost story, not a sustainability poster, even if the planet wins too.

Stéphane Gilbert came on (don't) Waste Water in 2020 framed, half in jest, as a forthcoming French-Tech unicorn, and he was refreshingly honest that the founder who starts a company is rarely the right person to run it once it gets big. Aquassay has not become a unicorn, but it has kept growing the patient way: its e-Water platform now runs across 140 sites in 23 countries, and in 2025 it raised about 1.5 million dollars led by France's Banque des Territoires to push the same idea further, into water utilities and whole territories, not just factory floors.

“The world of water is a hidden world. Everywhere in the factory, the water is inside the pipes, and a lot of things occur which nobody is taking into account because they don't see it. It's like if you had some new glasses. The first value added by the system is to make visible what was not visible.”

Stéphane Gilbert is, in the end, the rare founder who built the software because he already knew the pipes, and that order matters: Aquassay reads like a water engineer's product that happens to run in the cloud, not a data product that went looking for a problem.