Mumbai-born Priya Prakash remembers designing her own games and toys as a child. Now, the NID-trained designer works on crafting user experiences on mobile phones. She has led product design teams at BBC and Nokia, and holds patents for iPlayer and Nokia Asha. Based out of London, Priya now runs Design for Social Change (D4SC) that is working on community operating systems in smart cities. Excerpts from an interview with Sunit Arora: