REST API Development
REST APIs that developers actually want to use
We design and build REST APIs that are clean, well-documented, versioned from day one, and deployed to Azure with security built in. Whether you need a public developer API, an internal microservice interface, or a third-party integration surface, we deliver APIs that stand the test of time.
Contract-first REST API development
Contract-first API design
We start with an OpenAPI (Swagger) specification, agreed between your team and API consumers before build begins. This eliminates late-stage integration surprises and enables parallel development.
RESTful resource modelling
We design clean, intuitive resource hierarchies and HTTP verb semantics that follow REST constraints, making your API predictable, cacheable, and easy for developers to adopt.
Authentication & authorisation
We implement OAuth 2.0 / OpenID Connect, API key management, and role-based access control, with Azure Entra ID (formerly Azure AD) integration for enterprise identity scenarios.
Versioning & backwards compatibility
We implement versioning strategies from day one, so your API can evolve without breaking existing consumers. We plan deprecation timelines and communicate changes through standard headers and documentation.
Documentation & developer experience
We produce interactive OpenAPI documentation, code samples, and onboarding guides. If you're exposing a public developer API, we integrate with Azure APIM's developer portal for self-service credential management.
Testing, load testing & contract validation
Every API is tested with automated unit, integration, and contract tests. Before going live we run load tests to validate performance under expected and peak traffic conditions.
REST API experience you can verify
Public REST API delivery experience
We have taken a customer from zero to a live, publicly accessible REST API managed through Azure APIM, including contract design, security policy, developer portal, and load testing.
Azure-native deployment
Our REST APIs run on Azure App Service, Azure Functions, or AKS, with managed identity, private endpoints, Application Insights instrumentation, and CI/CD pipelines as standard.
Government API track record
We have enhanced the API layer of the UK Livestock Unique Identification System, a legally mandated national service, improving security, flexibility, and interoperability.
Standards-driven, not over-engineered
We follow REST conventions rigorously and resist the temptation to over-engineer. Clean naming, correct status codes, proper error bodies, and sensible pagination, the fundamentals that make an API a pleasure to consume.
Our REST API development process
A spec-first approach that keeps your consuming teams unblocked from day one.
Requirements & API Contract Design
We work with your team and representative consumers to document requirements and produce an OpenAPI specification. Endpoints, resource models, auth flows, error schemas, and versioning strategy are all agreed before build starts.
Build & Mock-First Development
We generate a mock server from the OpenAPI spec on day one, giving your consuming teams something to build against immediately. The real implementation is built in sprint cycles with regular demos and contract-compliance checks.
Security Review, Testing & Documentation
We run automated contract tests, integration tests, and a security review covering OWASP API Top 10 considerations. Interactive documentation is generated from the spec and reviewed with stakeholders before launch.
Deployment & Launch
We deploy via CI/CD to your Azure environment, configure Azure APIM if in scope, and run final load tests. Post-launch, the API is monitored through Application Insights with alerting configured for error rate and latency thresholds.
Frequently asked questions
What is the difference between REST and GraphQL? Which should I choose?
REST suits the majority of public APIs, webhook receivers, and CRUD-heavy backends, it's simpler to cache, easier to reason about, and supported by every HTTP client on the planet. GraphQL is better when your clients have varied, complex data needs across related entities, typically mobile and web front-ends. See our GraphQL API Development page for more detail. In many systems, REST and GraphQL coexist.
Should my REST API go through Azure API Management?
If you have external consumers, need rate limiting, want centralised auth enforcement, or plan to expose multiple APIs, yes. APIM gives you a governed, observable API surface without polluting your backend with cross-cutting concerns. See our Azure API Management page.
Do you write OpenAPI specs first, or code first?
We prefer spec-first for any API with external consumers or parallel development teams, it surfaces contract issues early and allows mock servers to be generated immediately. For purely internal APIs with a single consumer we may be more pragmatic, but we always produce an OpenAPI spec as a deliverable.
How do you handle breaking changes to an API?
We implement versioning from day one (/v1/, /v2/) and maintain a deprecation policy. Breaking changes are communicated through response headers (Deprecation, Sunset), documented in the developer portal, and given a supported sunset window before the old version is retired.
Can you take over an existing REST API that wasn't built by you?
Yes, we frequently take on inherited APIs. We start with a review of the existing codebase, spec, security posture, and test coverage, then produce a remediation plan before beginning any new feature work.
Explore the wider integration picture
Ready to build a REST API your consumers will love?
Book a free consultation with one of our API specialists to discuss your requirements, audience, and what a contract-first REST API project looks like with Talk Think Do.
Book a free consultationor call 01202 375647