API Design & Implementation
A well-designed API is what makes a system integrable. A poorly designed one becomes a maintenance burden that blocks every new integration project. We design APIs that are consistent, documented, and built around how the systems connecting to them actually work — including healthcare interoperability standards such as FHIR and openEHR REST.
Where API projects go wrong
Most API problems are design problems — not implementation problems. They show up later, when the API is already in production and hard to change.
No service layer at all
Systems built for internal use often have no API. When the business needs to connect a new application, share data with a partner, or expose functionality to a mobile client, everything has to be built from scratch — without a clear design to work from.
Inconsistent and undocumented APIs
APIs grown organically over time accumulate inconsistencies: different naming conventions across endpoints, inconsistent error responses, missing authentication on some routes, no versioning strategy. Each client that integrates has to reverse-engineer what the API actually does.
Point-to-point integrations that don't scale
When there is no shared API contract, each integration becomes a custom project. The team ends up maintaining a different connection for every system, and any change to the backend breaks multiple clients at once.
How we help
We cover the full API lifecycle — from the first design decisions to a working, documented implementation your team can maintain and extend.
API Design
We design REST APIs from the ground up: resource modeling, endpoint structure, request and response formats, error handling, authentication patterns, and versioning strategy. We produce a complete OpenAPI specification that serves as the contract between your API and the systems consuming it — before any code is written.
API Implementation
We implement APIs based on a formal design spec. This includes building the service layer, wiring it to your existing data model, writing tests against the OpenAPI contract, and documenting every endpoint with examples. We can deliver a working prototype to validate the design, or a production-ready implementation your team takes over.
Healthcare Interoperability APIs
We design and implement APIs that comply with healthcare interoperability standards: FHIR R4 REST APIs, openEHR ITS REST APIs, and HL7 v2 messaging interfaces. This includes defining the right profiles and extensions, handling terminology bindings, and validating conformance against the target specification.
API Client Development
When your application needs to consume an API provided by a third party — an EHR, a laboratory system, a terminology service, or a government health platform — we research the API, design the client integration, and implement it. We handle authentication flows, error recovery, and data mapping from the external model to yours.
API Review and Refactoring
If you have an existing API that is hard to use, poorly documented, or causing integration problems, we review it against REST design best practices and your specific use case. We identify what needs to change, design a migration path that does not break existing clients, and deliver a revised specification.
Integration Architecture
When the problem is not a single API but a system of APIs — multiple services, multiple clients, shared authentication, event-driven flows — we design the integration architecture that sits above the individual APIs. This includes choosing the right patterns (gateway, message bus, event streaming) and designing the contracts that make the whole system maintainable.
Do you have any questions?
Let us know how we can help you.