A DPI should not just be innovative in itself, but also enable diverse innovation by a public/private ecosystem of users.
A DPIs tech architecture should allow others (public and private innovators) to build solutions and services using the DPI at scale (akin to highways or the Internet) via tools such as open APIs (instead of DPI providers building the entire solution in a monolithic fashion).
Enable innovation both by ‘challenger’ market players in the ecosystem and by incumbents.
A digital back-end shouldn't presuppose a single digital front-end. Enable both the core DPI architecture and a diversity of innovative ecosystem-created solutions to power multi-modal access: across online, semi-online (low bandwidth connectivity), and offline modes; self-service and assisted modes; and in smartphone/feature phone/ no-phone modes.
For instance, payment systems or identity systems shouldn't presuppose just one mode of authentication (e.g. online API based) and allow for offline or semi-online modes (QR codes, local SDKs that can perform face authentication, etc.)
This is essential to catalyse private innovation that doesn't merely target an elite connected population in a country, but also innovates to solve the challenges of diverse populations who speak multiple languages and have varying levels of digital literacy - thus reducing the impact of a digital divide. The principle also addresses both scale and adaptability/sustainability over time.
Private Innovation can be leveraged both in building the DPI (for instance, in driving private partners to enroll individuals into an identity system) and in usage of the DPI in a wider digital economy to offer solutions (for instance, banks or private players using an identity eKYC to offer a service like opening a bank account).
Public/private adoption and innovation should be voluntary and demand-based rather than mandated by authorities. This tends to create sustained usage over time.