India, Aug. 8 -- Nine months ago, I moved from Brazil to India with what I thought was a reasonable frame of reference. Brazil and India share many characteristics. Both are continental-sized economies, home to young populations, entrepreneurial energy, and rapidly evolving digital ecosystems. Having spent years leading businesses in Brazil, I expected to find similarities.

What surprised me was not how similar the two countries are. It was how differently India has approached the challenge of building a digital economy at scale. In many parts of the world, digital transformation is still discussed as a future ambition. In India, it is increasingly becoming the default way society operates.

Brazil has Pix, its instant payment system, a...