Senior .NET Integration Developer

About Us

At MCS Rental Software, we’re passionate about helping rental businesses grow. With over 40 years of expertise, we provide cutting-edge rental management software, cloud solutions, and responsive technical support to companies around the world. Join our mission to empower the rental industry through smart technology and outstanding service.

The Opportunity

We are seeking a Senior .NET Integration Developer with a strong background in building and maintaining integrations with third-party systems. You will play a key role in ensuring our platform integrates securely and reliably with external systems – including financial services, telematics, and mapping APIs – while driving scalability, compliance, and automation across our integration landscape.

This is a high-impact role ideal for someone who thrives in a technically demanding environment and wants to help shape the integration architecture of a leading SaaS product used by rental businesses globally.

Key Responsibilities

• Integration Leadership: Lead the development and maintenance of robust, well-documented financial and third-party integrations.
• Framework Improvement: Enhance and evolve our integration framework, ensuring scalability and alignment with best practices.
• Partner Enablement: Support customers and partners with integration setup, offering expert guidance on APIs and gateways.
• Telematics: Extend and support our suite of telematics integrations, including features like event tracking and CO₂ reporting.
• Security & Compliance: Build with robust security, encryption, and data protection standards in mind.
• Operational Excellence: Promote observability with structured logging, monitoring, and clear documentation for all integrations.
• Knowledge Sharing: Contribute to internal knowledge bases and explore automation tools like Power Automate and Zapier to enhance both internal and customer-facing capabilities.

What We’re Looking For

• Extensive experience with C# / .NET (Core or Framework) in integration-heavy environments.
• Proficiency in building resilient, fault-tolerant systems using retry patterns, circuit breakers, and queues.
• Strong understanding of REST, SOAP/XML, asynchronous messaging, and event-driven architectures.
• Working knowledge of integration security, including authentication, encryption, and GDPR compliance.
• Excellent communication skills and the ability to produce high-quality technical documentation.
• Experience with monitoring, logging, and maintaining observable integration environments.

Desirable Experience

• Prior experience integrating with financial or ERP systems.
• Hands-on development of Open APIs with Swagger/OpenAPI documentation.
• Familiarity with Azure services and cloud-based automation tools (e.g., Power Automate, Zapier).
• Exposure to IoT or Telematics platforms and data handling.
• Awareness of standards like ISO 27001, SOC 2, or GDPR compliance.

Salary Range: £45-60k

Job Type: Hybrid (3days in office)

Why Work at MCS

We’re proud recipients of the Culture 100 Award, which recognises organisations that excel in nurturing their workforce, rewarding their staff, and creating a supportive environment where everyone feels valued.

At MCS, we pride ourselves on maintaining a vibrant, informal workplace culture based on respect and empowerment. Our dedication to our people has led to an average employee tenure of over 10 years.

You’ll be part of a forward-thinking team with the freedom to innovate and the opportunity to make a real impact in the rental technology space.