C# Integration Developer

Opus Recruitment Solutions; White Waltham; Hybrid; GBP 59,000 - 70,000; Full time

Job summary

A leading recruitment agency in the UK is seeking an experienced Integration Developer (C#) to work in a hybrid environment. The role involves building integrations with financial and telematics systems and requires solid C#/.NET experience, an understanding of modern APIs, and a security-first mindset. The position offers a salary of up to £70,000 and a collaborative culture that values longevity.

Benefits

Hybrid working

Competitive salary

Award-winning culture

Qualifications

• Solid experience with C#/.NET in integration-heavy environments.
• Deep understanding of REST, WebAPI, and event-driven architectures.
• Experience building fault-tolerant systems (retries, queues, circuit breakers).
• A security-first mindset (authentication, encryption, GDPR).
• Great communication skills.

Responsibilities

• Build and maintain integrations with financial systems, telematics platforms, and mapping APIs.
• Ensure everything runs smoothly, securely, and in line with GDPR.
• Help partners and customers set up integrations.
• Keep documentation, monitoring, and logging accurate.

Skills

C#/.NET experience

REST and WebAPI knowledge

Fault-tolerant system design

Great communication skills

Tools

Swagger/OpenAPI

Azure

Power Automate

Job description

Integration Developer (C#) – Hybrid in Maidenhead – Up to £70k

Are you an experienced Developer with a strong focus on APIs? We’re looking for an experienced C# Developer who knows their way around modern APIs like a pro and can make systems talk to each other.

For over 40 years, our client has been helping businesses thrive with smart tech solutions. Now, they need someone who can keep everything connected—securely, reliably, and with a sprinkle of brilliance.

What's in it for you?

Hybrid working: 3 days a week in the Maidenhead office, the rest from wherever you do your best thinking.

A salary up to £70,000 (because great talent deserves great pay).

A culture that’s won awards for being awesome (and yes, people like working here—the average tenure is over 10 years!).

What you’ll do

• Build and maintain integrations with financial systems, telematics platforms, and mapping APIs.
• Ensure everything runs smoothly, securely, and in line with GDPR.
• Help partners and customers set up integrations without needing a PhD in tech jargon.
• Keep things documented, monitored, and logged.

What we’re looking for

• Solid experience with C#/.NET in integration-heavy environments.
• Deep understanding of REST, WebAPI, and event‑driven architectures.
• Experience building fault‑tolerant systems (retries, queues, circuit breakers).
• A security‑first mindset (authentication, encryption, GDPR).
• Great communication skills—because explaining tech shouldn’t feel like decoding hieroglyphics.

Bonus points if you’ve

• Worked with financial or ERP systems.
• Swagger/OpenAPI experience.
• Worked with Azure or automation tools like Power Automate/Zapier.
• Dabbled in IoT or telematics.

To find out more, feel free to reach out to me directly with an up‑to‑date CV at (url removed) and we can have a chat.