At seventeen, Stanislas Niox-Chateau lost the future he had trained for since childhood. A serious back injury ended his hopes of turning professional at tennis.
He was no casual player. Born in Paris in 1987 and raised in Boulogne-Billancourt, the son of a nursery teacher and a computer scientist, he followed a sport-study programme from age ten. He won the international youth Open at twelve and was a six-time Paris junior champion, part of the same generation as Gaël Monfils and Jérémy Chardy.
He had seen up close how a simple booking tool could change an industry.
What many people who know the Doctolib name do not know is that he also fought a strong stutter as a young man. He eventually overcame it. Years later, through a family endowment called Okola, he would help fund support for children, stuttering among them.
After the injury he turned to books: a top science baccalauréat, the Saint-Louis preparatory class, then HEC Paris from 2006, where he became vice-president of the junior consultancy. In 2010 he joined investment fund Otium Capital and sat on the board of La Fourchette, the restaurant booking platform later bought by TripAdvisor. He had seen up close how a simple booking tool could change an industry.
In August 2013 he and co-founders Ivan Schneider, Jessy Bernal and Steve Abou Rjeily launched Doctolib, starting with about fifty practitioners. A clinic became its first user in June 2014. Money was small at first, four million euros in 2014 from investors including the PriceMinister founders. Hospitals, famously cautious, were the prize: the Paris public hospital network AP-HP integrated the service in 2016 and adopted it in 2017. A year later Doctolib bought its direct rival MonDocteur and its 55,000 professional users.
The cheques grew. 26 million euros in 2017 with Bpifrance, 150 million in 2019 at a one billion euro valuation, and 500 million in 2022 at 5.8 billion, the highest of any French startup at that moment.
Success brought scrutiny. Critics challenged its Amazon hosting and the encryption claims it had made. In 2021 it received a Big Brother Award. In November 2025 France's competition authority fined it 4.6 million euros for abusing a dominant position, a decision it is appealing. On the numbers, revenue was about 384 million euros in 2025 and the company says it turned profitable that fiscal year.
The tennis court taught him a habit he never dropped, to treat every booking slot as precious. Losing the sport at seventeen gave him a second chance to start from zero. Many founders discover that the thing that breaks them is the thing that points them to the work.