What Is the European Digital Stack, and Which Layer Is Missing

For more than a decade Europe has approached digital sovereignty primarily through regulation. GDPR, data protection legislation, the emerging AI rulebook and a succession of cloud governance initiatives have shaped the policy landscape of the digital economy, and Europe has shown remarkable leadership in defining the rules of the digital age. Yet regulation alone does not create technological sovereignty. A deeper question is now emerging: if Europe seeks genuine digital sovereignty, what will its technological foundations actually look like?

From regulation to architecture

This is where the idea of the European Digital Stack becomes relevant. Rather than concentrating on rules and compliance frameworks, the concept shifts the discussion to the technological architecture a sovereign digital ecosystem would need. In practical terms it refers to the layered infrastructure that enables digital services across the continent: digital identity, secure data exchange, cloud infrastructure, AI platforms, trusted APIs and digital payment infrastructures. Together, these layers form the operational backbone of Europe’s digital future.

Several of those capabilities already exist in some form. Digital identity initiatives such as eIDAS aim to provide trusted identification across borders. Secure data exchange frameworks allow institutions and companies to collaborate while keeping control of sensitive information. Cloud infrastructure, increasingly deployed within European regulatory and operational frameworks, provides the computational backbone on which modern services run. And modern ecosystems depend on the layers above: trusted APIs for secure interaction between systems, payment infrastructures for cross-border economic activity, AI platforms that turn raw data into something actionable.

What makes the European Digital Stack significant is precisely that it moves the conversation from policy to architecture. Digital sovereignty cannot be achieved solely by regulating technology providers. It emerges from an ecosystem in which the core building blocks are interoperable, trusted and governed according to European legal and institutional principles.

The EuroStack vision

This shift in perspective is already visible in recent policy discussions. The EuroStack report proposes a comprehensive vision for rebuilding Europe’s digital ecosystem across every technological layer, and the challenge it describes is substantial: around 80 percent of Europe’s digital infrastructure and technologies originate outside the continent, creating structural dependencies on non-European providers and limiting Europe’s ability to shape its own trajectory. EuroStack proposes a different direction, a European digital ecosystem built on interoperable building blocks and operated by European institutions, companies and public administrations.

The vision describes a layered environment of digital identity systems for secure authentication across borders, data exchange frameworks for trusted information sharing, cloud infrastructure for scalable computing, AI platforms for advanced analytics, trusted APIs for interoperability and payment infrastructures for cross-border transactions. Taken together these could become a common European digital infrastructure. At its core sits a principle that has long defined European digital policy: security by design and privacy by design. Critical infrastructure must operate within European legal frameworks while guaranteeing strong protections for personal and institutional data.

Europe’s digital building blocks

None of this is purely theoretical. Since 2014 the European Commission has been developing Digital Building Blocks under the Connecting Europe Facility programme: reusable technological components that Member States can adopt to implement interoperable services. The most important are eID for cross-border digital identity, the upcoming EUDI Wallet, eSignature for legally recognised digital signatures across the EU, eDelivery for secure cross-border data exchange and EBSI, the European Blockchain Services Infrastructure. These infrastructures already support hundreds of cross-border public-sector use cases, from taxation and customs procedures to education and judicial cooperation.

One of the most interesting implementations is the Once-Only Technical System. OOTS allows public administrations to exchange authentic documents such as birth certificates or business records across Member States without asking citizens to submit the same information again and again. Technically it combines eID for authentication, eDelivery for secure exchange and interoperable APIs for cross-border services. The result is, in effect, a European public-sector data space operating across national boundaries.

The missing layer

Most discussions around EuroStack focus on cloud providers, semiconductor manufacturing or AI models. Those layers are undeniably important, but the conversation routinely overlooks a critical component of digital sovereignty: the data platform layer. Every digital service ultimately depends on the ability to store complex data structures, manage evolving data models, integrate data from multiple systems, share it across jurisdictions and power search, analytics and AI. In other words, digital sovereignty requires sovereign data architectures. Without robust data platforms, digital infrastructures risk becoming fragmented and hard to scale across borders.

The role of hyperscalers

A natural question follows. If Europe aims to build its own stack, what role will hyperscale cloud providers play? The reality is that Europe’s digital infrastructure will almost certainly remain hybrid and multi-vendor. Hyperscalers provide global scale, operational reliability and advanced compute, while European policy increasingly insists on jurisdictional control, data portability, vendor independence and open standards. In that environment the architecture of digital platforms becomes more important than the identity of the infrastructure provider. Systems must be designed to stay portable, resilient and interoperable across several cloud environments.

The data platform layer

Modern public-sector platforms are no longer simple databases behind monolithic applications. They have to support complex and evolving data models, distributed architectures, high-volume operational workloads, integrated search and analytics, real-time processing and AI-driven services. In this context modern document-oriented data platforms have become increasingly relevant, because they let governments and public institutions manage complex, evolving data structures while supporting distributed architectures and integrated analytical capabilities.

Platforms such as MongoDB Atlas illustrate the approach: distributed, multi-cloud data services able to operate across regions and jurisdictions while preserving operational flexibility and avoiding infrastructure lock-in. That architectural model aligns closely with Europe’s broader objective of keeping technological sovereignty while preserving openness and innovation.

Digital sovereignty ultimately requires more than infrastructure investment. It requires architectural choices that enable sovereignty by design: distributed data architectures, multi-cloud deployment strategies, open interoperability standards, jurisdiction-aware data governance and flexible data models able to evolve with regulation. Europe has already shown, through the Digital Building Blocks programme, that it can build interoperable digital public infrastructure. The next step is making sure those infrastructures rest on data platforms capable of handling the scale and complexity of the European ecosystem.

Why it matters

The EuroStack vision signals a new phase in Europe’s digital transformation. Rather than focusing solely on regulation, Europe is beginning to build the technological foundations of its own ecosystem. The Digital Building Blocks show that shared infrastructure can operate across borders while respecting national governance; the next challenge is scaling those foundations into digital public infrastructures able to support the entire single market.

The future of European digital sovereignty will not depend solely on cloud providers or AI models. It will also depend on the design of the data platforms that power Europe’s public services. The construction of the European Digital Stack is only beginning, and the architectural choices made today will shape the next generation of digital services across the continent. In many ways, the real architecture of Europe’s digital future will be decided not only in legislation but in the design of the platforms that underpin its public and economic systems.