The problem
A UK healthcare services provider relied on a long-established Microsoft-based ERP as the system of record for operational and patient-linked workflows. The platform was stable and heavily customised, but integration options were limited, and change carried high operational and clinical risk.
To enable modern digital services and the exchange of patient demographics in the future with external and national-level services, the organisation needed an integration approach that supported asynchronous processing, strong identity and access controls, full auditability, and safe write-back into the legacy ERP - without a disruptive replacement programme.
The solution
A decoupled, event-driven integration architecture was implemented on a Microsoft technology stack. Containerised .NET microservices exposed stable integration contracts, orchestrated long-running workflows, validated and reconciled patient data, and applied controlled updates back into the ERP. The design prioritised resilience, security, and observability.
API Gateway
Azure API Management provided a governed front door with OAuth2/OpenID Connect, throttling, schema validation, and request/response transformation.
Workflow Orchestrator
A .NET service (hosted on Azure Container Apps/AKS) implemented sagas for multi-step processes such as demographic verification, approval, and write-back.
Messaging Backbone
Azure Service Bus queues/topics decoupled producers and consumers, enabling retries, scheduled messages, and dead-letter handling for failures and exceptions.
Validation & Matching
Microservices normalised and validated demographics, applied configurable matching rules, and generated reconciliation outcomes with clear reason codes.
Controlled Write-back
An idempotent update service applied approved changes to the ERP via supported integration points, using an outbox pattern to prevent partial updates.
Security & Observability
Microsoft Entra ID, Key Vault, and Azure Monitor/Application Insights enforced least-privilege access, protected secrets, and provided full audit trails and dashboards.
The benefits
Safer Data Exchange
Field-level controls, validation, and reason-coded reconciliation reduced risk when sharing or updating sensitive demographics.
Faster Integration Change Cycles
Microservices and API contracts reduced coupling, enabling small, testable releases without modifying the legacy ERP.
Higher Data Quality
Automated normalisation, deduplication support, and authoritative checks improved demographic accuracy at the point of use.
Resilience by Design
Service Bus retries, dead-letter queues, and idempotent handlers prevented message loss and avoided duplicate updates.
Strong Governance & Audit
Centralised logging, correlation IDs, and immutable audit records improved assurance for compliance and clinical safety review.
Cloud-Ready Foundation
The integration layer created a reusable pattern for future services and reduced risk for any eventual platform migration.
