TED Resident Keith Kirkland and his team at WearWorks use haptic technology to develop products and experiences that communicate information through touch. In 2017, they were faced with a seemingly impossible challenge: quickly develop a device for a blind ultra-marathon runner to compete -- unaided and unassisted -- in the New York City Marathon. Jennifer Brook, a design researcher at Dropbox, explains how the team at WearWorks navigated the challenges and tensions of designing this groundbreaking new technology.