Clinical data aggregation hub

The problem

Internal teams accessed many clinical data sources through different APIs, each with its own authentication, schema, and quirks. Every consumer reimplemented the same client logic; a schema change broke many call sites; request budgets were uncoordinated, causing rate-limit cascades. Each new data source meant another integration project per consuming team.

The approach

We built a .NET API hub with ASP.NET Core that aggregates clinical data sources behind a single read-friendly contract. A typed C# SDK ships to downstream services; endpoints version on schema; request budgeting enforces fair use; request-level audit captures who asked for what when. New data sources register via adapter interfaces, so onboarding a partner is a hub-side change, not a consumer-side change.

Stack and engineering choices

• ASP.NET Core API hub
• Typed C# client SDK
• Schema-versioned endpoints
• Request budgeting
• Per-request audit log
• Adapter interface for sources
• Read-friendly contract

Outcome

Internal teams build against one SDK instead of a dozen origin APIs. Schema changes are absorbed at the hub layer; consumers do not break. Request budgeting prevents one consumer from starving the rest, and audit answers compliance questions about who accessed what.