Architecture Principles

1. Start with User Needs

Digital services must be designed around the identified, evidence-based needs of their users.

2. Design for Change

Digital services must be architected to be loosely coupled and highly cohesive, enabling them to evolve easily and safely over time.

3. Embed Security and Privacy by Design

Security and privacy must be treated as core quality attributes, embedded throughout the entire service lifecycle from inception to decommissioning.

4. Use the Welsh Health Data Space

Services should read from and write to the Welsh Health Data Space, contributing to a single, comprehensive record for each citizen. This supports both longitudinal records and real-time pathways while maintaining flexibility around architecture and integration patterns.

5. Enable Interoperability with Open APIs

All digital services must expose their data and functionality through well-defined, secure, and open APIs.

6. Select for Reuse, Use Shared Platforms

Digital services must reuse existing common platforms and components when they meet the requirements and range of user needs. New components must be designed or selected for reuse unless a clear exception is justified.

7. Deliver Sustainable and Affordable Services

Digital services must be designed, delivered, and operated in a financially, technically, and environmentally sustainable manner throughout their entire lifecycle.

8. Be Cloud Capable

Public cloud is the default hosting environment for all new and modernised digital services. Any alternative deployment model requires a documented and approved exception.

9. Build for Modern Browsers

User-facing digital services must be browser-based, responsive, and compliant with current web and accessibility standards.

10. Design for Public Internet

Digital services must be built using modern, open, and widely adopted internet standards and protocols.