API Development & Integration

Connecting Systems, Unlocking Data

Modern businesses rarely run on a single application. You have a CRM, an accounting package, a website, perhaps a mobile app, various third-party services, and internal tools that have accumulated over the years. The challenge is getting these systems to talk to each other reliably, securely, and without someone manually copying data between them.

That is where API development comes in. A well-designed API acts as the backbone of your technology infrastructure, allowing your systems to share data and trigger actions automatically. At Dev Team Solutions, we have been building APIs and system integrations for over 25 years — long before “API-first” became a buzzword.

Our Approach

RESTful API Design

We design and build RESTful APIs using ASP.NET Web API and .NET, following industry best practices for resource modelling, versioning, error handling, and documentation. Our APIs are built to be consumed easily by any client — whether that is a web front-end, mobile app, third-party service, or internal system.

Every API we build includes comprehensive documentation, consistent response formats, and sensible versioning so that your API can evolve without breaking existing consumers.

GraphQL for Complex Data Requirements

For applications with complex data relationships or front-ends that need flexible querying, we also build GraphQL APIs. GraphQL lets your clients request exactly the data they need in a single request, reducing over-fetching and improving performance — particularly useful for mobile apps where bandwidth matters.

Third-Party Integrations

We integrate your systems with a wide range of third-party services and platforms:

• Payment providers — Stripe, PayPal, GoCardless, and other payment gateways
• Accounting software — Sage, Xero, QuickBooks, and FreeAgent
• CRM platforms — Salesforce, HubSpot, Dynamics 365, and custom CRMs
• Email and communications — SendGrid, Mailchimp, Twilio, and Microsoft 365
• Recruitment platforms — job board feeds, applicant tracking systems, and CV parsing services
• Government and public sector APIs — Companies House, HMRC, NHS, and local authority data feeds

We handle the authentication, data mapping, error handling, and retry logic so that your integrations work reliably in production, not just in demos.

Middleware and ETL Pipelines

Sometimes the integration challenge goes beyond simple API calls. When you need to move large volumes of data between systems, transform formats, apply business rules, or orchestrate complex workflows across multiple services, we build middleware and ETL (Extract, Transform, Load) pipelines that handle the heavy lifting.

These pipelines can run on a schedule, react to events in real-time via webhooks, or be triggered manually — whatever fits your business process.

API Security

Security is not an afterthought. Every API we build includes:

• OAuth 2.0 and OpenID Connect for industry-standard authentication and authorisation
• API key management for service-to-service communication
• Rate limiting and throttling to protect against abuse
• Input validation and sanitisation to prevent injection attacks
• HTTPS everywhere with proper certificate management
• Audit logging so you know who accessed what and when

For APIs that handle sensitive data, we implement additional measures such as field-level encryption, IP whitelisting, and mutual TLS authentication.

Azure API Management

For organisations with multiple APIs or complex integration landscapes, we deploy and configure Azure API Management as a central gateway. This gives you a single point of control for authentication, rate limiting, analytics, and developer portal access across all your APIs.

Why It Matters

A well-built API is not just a technical nicety — it is a business asset. It lets you:

• Automate manual processes that currently require someone to copy data between systems
• Launch new products faster by building on existing services rather than starting from scratch
• Open your platform to partners who can integrate with your systems through a documented API
• Improve data consistency by having a single source of truth that all systems read from
• Scale your technology without replacing everything when your business grows

Get Started

Whether you need a new API built from scratch, an integration between existing systems, or help modernising a legacy integration that has become unreliable, we can help. Contact us to discuss your requirements.