Bryan Johnson is a prominent American entrepreneur and venture capitalist known for founding major technology firms such as Braintree, Kernel, and the OS Fund. After selling his payment processing company to PayPal for hundreds of millions of dollars, he pivoted his focus toward neuroscience and the study of human longevity. He is most recognized today for Project Blueprint, an intensive and expensive self-experimentation regimen designed to drastically reverse his biological age. While his efforts have garnered significant media attention and documentary features, they have also faced scientific skepticism and scrutiny regarding his use of strict confidentiality agreements. Despite these controversies, Johnson remains a leading figure in the transhumanist movement, frequently publishing works and sharing data on his personal health journey.