The 99PI Anniversary Special: 15 for 15

In this 15th-anniversary episode of 99% Invisible, host Roman Mars answers 15 questions from listeners and producer Vivian Leigh, covering a range of topics related to design, the show's history, and Mars' personal experiences. Questions include how to improve a city without spending money, the evolution of the definition of design, a designed object deserving a second chance, and a design-related hill Mars is willing to die on. Mars also discusses his past job delivering pizzas, the process of creating a 99PI episode, dream merchandise, and design decisions he may have influenced. The episode concludes with a bonus question about his twins, including a clip of them from an early episode.