API development service
Freelance API developer for integrations, backend services, and structured data systems
I design and build REST APIs, backend services, integration layers, and machine-readable data systems for products that need clear contracts and reliable behaviour. That includes greenfield API development, third-party integrations, webhook flows, backend refactors, and systems where data modelling matters as much as the endpoints themselves.
Delivery areas
What I cover in API development
- REST APIs and internal service layers with clear contracts
- Third-party integrations, data ingestion, and webhook handling
- Validation, auth, errors, and documentation that make the API easier to use
- Domain and schema modelling that supports future change without constant rewrites
Engagement timing
When to bring me in
- Integrations keep breaking or are hard to reason about
- The backend needs better shape before more features are added
- The data model is fighting the product instead of supporting it
- You need an API developer without bringing in a full agency
Project flow
How API and backend engagements usually work
1. Architecture and constraints
We look at the consumers, integrations, data model, and operational risks so the backend is designed around real usage rather than guesses.
2. Implement the service layer
I build or improve the API directly, keeping contracts, validation, and system behaviour clear for both current users and future maintainers.
3. Stabilise and hand over
The goal is a backend that is easier to extend, safer to operate, and less stressful to build on after the initial delivery.
Case studies
Relevant API and backend engineering work
These projects reflect the kind of API design, backend modelling, and integration-heavy work I take on: systems where correctness, long-term structure, and machine-readable outputs matter.
Revision-Centric Knowledge Base Backend
REST APIs, transactional backend logic, validation, publishing workflows, and revision-aware data modelling.
Semantic Knowledge Platform and Identity Infrastructure
Structured data architecture, API-facing backend services, automation, and production delivery.
Next step
Need a freelance API developer or backend engineer?
Share the current stack, the parts that feel brittle, and the shape of the consumers using the API. That might mean a new REST API, a backend clean-up, an integration-heavy service, or a data model that needs redesigning. If you need a broader product build around that backend, my software development service covers the wider delivery side as well.