When Nandan Nilekani, the architect of India’s unique identity programme, put together a ragtag team of developers to work on the future of digital payments in the country, the codename given to one of the key projects was ‘Panga Project’.

Panga, which roughly translates to ‘taking on’ in Hindi, was an apt name since the unofficial goal of the programme was to beat global giants such as MasterCard and Visa and break their monopoly in payments. What Nilekani’s team built, laid the foundation for the Unified Payments Interface (UPI), a platform that ...