C# Integration Developer

Opus Recruitment Solutions; Maidenhead; Hybrid; GBP 60,000 - 70,000; Full time

Job summary

A leading tech recruitment agency is seeking an experienced C# Integration Developer for a hybrid role in Maidenhead. You will build and maintain integrations with financial systems and APIs, ensuring security and compliance with GDPR. The ideal candidate has solid experience with C# and .NET, and skills in REST and WebAPI. This position offers a salary of up to £70,000 and a positive culture with high employee tenure.

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.
• A security-first mindset focusing on authentication and encryption.

Responsibilities

• Build and maintain integrations with financial systems and APIs.
• Ensure operations run smoothly while aligning with GDPR.
• Document, monitor, and log integration processes.

Skills

C# / .NET

REST

WebAPI

event-driven architectures

fault-tolerant systems

communication skills

Tools

Swagger / OpenAPI

Azure

Power Automate

Zapier

Job description

C# Integration Developer

Maidenhead, United Kingdom

Permanent

£60000 - £70000 per annum

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

Been coding integrations since before APIs were cool? Perfect. 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.

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

What’s in it for you?

• Hybrid working : 3 days a week in their 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—average tenure is over 10 years!).

What you’ll do :

• Build and maintain integrations with financial systems, telematics platforms, and mapping APIs.
• Make sure everything runs smoothly, securely, and in line with GDPR (because nobody likes compliance headaches).
• 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.
• Skills in building fault-tolerant systems (think 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.
• Played around 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 and we can have a chat.