A baby was sick, and nobody could say why. Claire Novorol, then a young clinician in clinical genetics, went looking. At Addenbrooke's Hospital in Cambridge she searched the medical literature and scientific databases until she found a rare genetic condition that matched. The baby was diagnosed. That episode, as the story is told, is where the idea began.
It stuck with her because of what it exposed. The answer had existed in print all along. It had taken hours of one doctor's evening to find it, and most children with rare diseases do not have a doctor like that.
The first product was a decision-support tool for doctors working on rare diseases.
Novorol did not leave medicine for software straight away. She started Doctorpreneurs, a network for doctors interested in building digital health products. Through it she travelled to Berlin and met two people who would become her co-founders: Daniel Nathrath, who became CEO, and Martin Hirsch, who became CTO. In 2011 they founded Ada.
The first product was a decision-support tool for doctors working on rare diseases. It was accurate, but it was small. Doctors are a thin market, and the tool needed the very people who already had the least time.
What changed things was a pivot. In 2016 the company turned the engine around and pointed it at patients, creating a symptom checker called Assess. Anyone could answer questions and get a list of possible causes. It was tested against rival apps in 2017 and did well, and a 2019 retrospective study found that its top suggestion matched the confirmed diagnosis in 83 of 93 rare disease cases, about 89 percent.
The price of going consumer was scrutiny. A tool that tells strangers what might be wrong with them must be certified, audited and defended. Ada runs a quality system to the medical device standard ISO 13485 and its software is CE-certified as a Class IIa medical device in Europe. That is slow, expensive work, and it is the opposite of the move-fast story most apps tell.
By 2017 the company had raised about $47m, and by 2023 it employed roughly 300 people. A later, larger Series B of over €105m has been reported.
The lesson is a doctor's one. Novorol did not start from a market gap. She started from a single patient, and from the discomfort of knowing that the answer existed somewhere. Founders who begin with one person's problem rarely run out of reasons to keep going.