Markus Muller, co-founder of Flinn, shares his journey of testing ideas and building a business in the healthcare industry. 

He emphasizes the importance of testing assumptions and using experiments to validate ideas. Markus discusses the use of LOIs (Letters of Intent) as a tool to gain commitment from potential customers. 

He also highlights the value of co-creation with customers and the need to balance risk in heavily regulated industries. Overall, Markus provides insights into the testing mindset and its application in building a successful business.