Connect your systems
with APIs built to last

APIs are the connective tissue of modern software. We build APIs that let your systems communicate reliably and your platform scale without accumulating the technical debt that brings everything to a halt.
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Poorly designed APIs cost you twice

We build APIs that connect, 
perform, and integrate

We bring rigorous engineering discipline to every integration challenge. From RESTful APIs and GraphQL to third-party integrations, we build the connectivity layer your systems depend on.

Our API development service capability

We take a design-first approach to API development, working with your engineering and product teams to build integration layers that are performant, secure, and genuinely easy to work with.
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RESTful API design & development

We design and build REST APIs that are intuitive, consistent, and built to handle the demands of production traffic.
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GraphQL API development

We build GraphQL APIs that give clients flexible, efficient data access without the over-fetching REST introduces at scale.
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API strategy & architecture

We define the API strategy your platform needs, designing the integration architecture, naming conventions, and versioning.

Third-party API integration

We build robust third-party API integrations, handling authentication, rate limiting, and edge cases.
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API documentation

We produce clear, accurate API documentation so teams and partners can integrate quickly without needing the source code.
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API security & authentication

We implement authentication, authorisation, and security controls for your APIs, from OAuth 2.0 and JWT to rate limiting.
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API performance & load testing

We test APIs under realistic production load, identifying bottlenecks and capacity limits that only appear at scale.

API versioning & lifecycle management

We implement versioning strategies that allow your APIs to evolve without breaking the consumers that depend on them.
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Webhook development

We build event-driven webhook systems that enable real-time communication between your platform and external services.
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API monitoring & analytics

We implement monitoring and alerting that gives full visibility into API performance, error rates, and usage patterns.
“

Online ordering of JCB equipment has proved to be extremely popular. The JCB Machine Store marks a significant evolution of the concept with more machines, more options, and more insight available than ever before. We have invested heavily in creating a high-quality platform tailored to the needs of an evolving market and a new generation of customers.

We succeed together.

How we built a No.1 app
 for Center Parcs guests

Over 70,000 downloads in its first week, a 15% uplift in bookings, and No.1 in the travel app charts. We designed a native iOS and Android app that made it simpler for Center Parcs guests to plan, book, and get the most from their stay.

Our API development approach is built on one thing:
Design the contract before you write the code

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Design before you build

We invest in API design before implementation, defining clear contracts and conventions that make integration straightforward for every developer.
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Document as you go

We document every API with the same rigour as the code. Clear, accurate documentation so teams integrate quickly without needing to read the source.
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Test for failure, not just success

We test against high load, malformed inputs, and network failures. Building for failure modes, not just happy paths, is what makes the difference.

We build APIs your systems 
can depend on

Atomic's API development team designs and builds the integration layer your systems depend on, with the performance, reliability, and documentation that make every integration straightforward.

Got questions about API development? We've got answers.

Get in touch

API development is the process of designing, building, and maintaining application programming interfaces that allow your systems, products, and third-party services to communicate reliably.

When existing integrations don't meet your requirements, when you're building a product that needs to share data with other systems, or when you need to expose your data securely.

REST uses fixed endpoints and is widely adopted and straightforward to implement. GraphQL gives clients control over what data they request, reducing over-fetching in complex applications.

Through authentication and authorisation (OAuth 2.0, API keys, JWT), rate limiting, input validation, encrypted transport, and regular security testing against OWASP API security guidelines.

We design APIs with versioning built in from the start, using clear strategies that allow your API to evolve without breaking existing integrations or forcing disruptive client updates.

Through automated functional testing, contract testing, performance testing, and security testing. We test every endpoint, edge case, and failure mode before an API goes into production.

A focused API project typically takes four to eight weeks from design to delivery, depending on the number of endpoints, integration complexity, and the systems it needs to connect.

API development investment varies by scope, complexity, and the number of integrations required. We scope every project individually and give a clear estimate after an initial conversation.

A clear brief on what the API needs to do, which systems it needs to connect, any existing API documentation, and access to the systems we'll be integrating with.

Yes. We build APIs and integrations designed to work with your existing architecture, handling the technical complexity of connecting legacy systems, third-party platforms, and modern services.

Explore our related services

Technical planning

The technical foundation your build depends on

We define the architecture, technology choices, and engineering constraints that give your project the clarity it needs to build accurately, on time, and to the right standard.

Web development

Platforms built to perform and grow

We build fast, accessible, and secure web platforms using modern technologies, designed to scale with your business and stay reliable over time.

Cloud infrastructure

Infrastructure that scales as you do

We design, build, and manage cloud environments on AWS, Google Cloud, and Azure, delivering the reliability, security, and cost efficiency your product needs to operate at scale.

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