Foundational digital public infrastructure (DPI), consisting of unique digital identification, payments system and data exchange layer has the potential to support the transformation of the economy and support inclusive growth. India’s foundational DPI, called India Stack, has been harnessed to foster innovation and competition, expand markets, close gaps in financial inclusion, boost government revenue collection and improve public expenditure efficiency. India’s journey in developing a world-class DPI highlights powerful lessons for other countries embarking on their own digital transformation, in particular a design approach that focuses on shared building blocks and supporting innovation across the ecosystem.