API Development That Connects Your Systems Properly

REST and GraphQL APIs designed, built and documented by UK engineers. A single integration ships in 2–4 weeks; most API projects run £5k–£15k with a fixed quote before work starts.

Bridging Systems. Unlocking Data Value.

In the modern enterprise, data isolation is a critical bottleneck. Disconnected systems lead to operational inefficiencies, manual workarounds, and missed opportunities for innovation. Your API infrastructure is the nervous system of your business, enabling reliable communication between internal tools, customer-facing applications, and third-party partners.

We design and engineer high-performance APIs that serve as the secure, scalable backbone of your digital ecosystem. From internal system integration to public-facing platforms, our APIs are built for speed, security, and developer experience. We ensure your data flows securely between applications, partners, and customers without friction, empowering you to launch new products faster and create cohesive, data-driven user experiences.

Infrastructure for the
Connected Enterprise.

Your API is a product. We build it with the same rigour, security, and performance standards as your core application.

High-Performance REST & GraphQL

We design APIs that handle high concurrency with low latency. Whether you need the standardisation of REST or the flexibility of GraphQL, we engineer interfaces that deliver data precisely when and where it is needed, without overhead.

Enterprise-Grade Security

An open door must still be guarded. We implement rigorous authentication (OAuth2, OIDC), rate limiting, and encryption protocols to ensure that your data remains accessible to authorised partners but impenetrable to threats.

Smooth Third-Party Integration

We don't just build APIs; we connect them. From CRM giants like Salesforce to payment processors and legacy ERPs, we unify disparate systems into a cohesive, synchronised operational whole.

Microservices Orchestration

Decompose monolithic rigidity into agile efficiency. We help you transition to microservices architectures, using APIs as the communication fabric that allows independent scaling and rapid deployment of new features.

Developer Experience (DX)

A great API is easy to use. We prioritise comprehensive documentation (Swagger/OpenAPI), intuitive endpoints, and SDK generation to ensure your internal teams and external partners can integrate with zero friction.

Real-Time Data Streaming

For businesses where seconds matter, we implement WebSockets and event-driven architectures. This ensures your users receive live updates—stock prices, inventory, notifications—instantaneously.

What a typical engagement looks like

Typical budget£5k–£15k
TimelineSingle integration 2–4 weeks; full API layer 6–10 weeks
CadenceA working demo or report every two weeks — you watch it grow.
OwnershipSource code, files and IP handed over in full. No lock-in.
First stepA free estimate or a free 30-minute call — fixed, staged quote before any work starts.

Proof, not promises

Case study

NEXT — in-store appointment booking

Booking, store and customer systems connected for a national retailer.

View case study

500+ projects delivered since 2005  ·  4.5★ on Google  ·  Crown Commercial Service supplier

Frequently asked questions

How much does API development cost in the UK?
Most API projects land between £5k and £15k — a single integration with an existing platform can be less, a full API layer across several systems more. You get a fixed, itemised quote before any work starts.
How long does an API integration take?
A single third-party integration typically ships in 2–4 weeks. A complete API layer for your product usually takes 6–10 weeks, delivered in fortnightly increments you can test.
Can you integrate with our existing software?
Yes — that is the usual starting point. We build against whatever you run today (CRM, ERP, payments, logistics or in-house systems) and document every endpoint so your team owns it outright.
What does the process look like?
A short discovery call, then a fixed itemised quote. We build against a sandbox first, document every endpoint as we go, and ship in fortnightly increments you can test against your own systems.
Which technologies do you work with?
REST and GraphQL, with OpenAPI documentation as standard. We integrate with CRMs, ERPs, payment providers, logistics platforms and in-house systems — whatever you already run.
What happens after launch?
You get full documentation and the source, so your team can own it outright — or we monitor and maintain the integration under a support plan with response times agreed in writing.
Ready for What’s Next?

Let's Build What's Next — Together

Not sure this is the right move yet? A free 30-minute call will tell you — no deck, no obligation.

4.5★ on Google reviews  ·  500+ projects delivered  ·  Crown Commercial Service supplier

020 8363 4905  ·  info@designdirect.io  ·  UK & India