On October 12, 2019, Eliud Kipchoge produced the fastest performance ever for a marathon distance, finishing in a time of 1:59:40.2. As a critical member of the performance team, I will present some of the developments that led to the world's first sub 2-hour marathon. From the aerodynamic formation, to the data that brought us to Vienna, these are some of the challenges we overcame to deliver the most crucial aspects of optimizing Kipchoges's performance