Digital public infrastructure (DPI) denotes foundational digital systems that serve as essential enablers for delivering digital services at scale across society. It has emerged as a key enabler of innovation in developing countries by reducing systemic entry barriers and fostering an inclusive digital ecosystem. DPI serves as a vital connective tissue within the digital ecosystem. Bridging the gap between physical infrastructure—such as internet connectivity, devices, data centers, and the cloud—and a diverse landscape of applications, DPI empowers societies to deploy innovative solutions across sectors like e-commerce, social protection, remote education, and telehealth. Real-world illustrations abound: India’s Aadhaar system has revolutionized digital identification, Brazil’s Pix has made fast, real-time payments accessible nationwide, and Australia’s Consumer Data Right is pioneering user-centric data sharing. By enabling dynamic, cross-sectoral innovation, DPI stands as the engine powering the next generation of digital transformation. This paper analyses the evolution and impact of India Stack, focusing on how its layers enable innovation across sectors such as fintech, health, and e-commerce. By mapping the structural features of India Stack against the outcomes in financial inclusion, digital health, and market decentralization, the paper offers a conceptual framework to assess the role of public policy in driving innovation. The findings indicate that when government platforms are built as public goods with interoperable standards and strong institutional backing, they can create an enabling environment for grassroots and enterprise-level innovation. The India Stack model, while context-specific, holds valuable lessons for other nations seeking to integrate public policy with digital transformation goals.