Senior .NET Developer

MRJ have partnered with one of the UK's leading technology businesses as they continue to invest in their engineering capability following the successful migration to their own proprietary platform.

With millions of customers and an ambitious technology roadmap, this is an exciting opportunity to join a business building innovative products at scale. You'll become part of a collaborative Agile engineering team responsible for developing and evolving the backend services that power a high-availability, customer-facing platform.

The Role

We're looking for an experienced Senior .NET Developer who enjoys solving complex engineering challenges and delivering high-quality software within a modern Agile environment.

You'll work across the full software development lifecycle, building scalable backend services, APIs and integrations while collaborating closely with Product, QA and Platform Engineering teams. This is a hands-on engineering role where you'll have ownership of features from design through to production, contributing to engineering standards, platform improvements and continuous delivery practices.

Key Responsibilities

• Design, develop and maintain scalable applications using C# and .NET.
• Deliver new features and enhancements across a large-scale customer platform.
• Build and maintain RESTful APIs, backend services and third-party integrations.
• Write clean, reusable and maintainable code following engineering best practices.
• Own developments from initial design through to production deployment and ongoing support.
• Collaborate closely with Product Managers, QA Engineers and Platform teams throughout the delivery lifecycle.
• Contribute to the evolution of CI/CD pipelines and development automation.
• Ensure solutions are fully testable through unit, integration and performance testing.
• Optimise application performance across SQL and NoSQL environments.
• Support continuous improvements across architecture, engineering standards and development processes.

Person Requirements

• Significant commercial experience developing applications with C# and .NET.
• Strong understanding of Object-Oriented Programming principles and software design patterns.
• Experience building Web APIs, Web Services and distributed applications.
• Experience working with SQL and NoSQL databases.
• Knowledge of N-Tier Architecture and service-oriented design.
• Experience using Git within collaborative development teams.
• Experience working within Agile or Kanban delivery environments.
• Strong understanding of software architecture and engineering best practice.
• Excellent problem-solving skills with a proactive approach to delivery.
• Strong communication skills with the ability to collaborate across technical and non-technical teams.

Desirable Experience

• Experience with WinForms or WPF.
• Experience working within betting, gaming or other high-volume transactional environments.
• Previous ownership of a product, platform or subsystem.
• Exposure to Microsoft Orleans, Windows Services, messaging platforms or caching technologies.

Tech Stack

C# | .NET | SQL | NoSQL | Web API | WCF | Microsoft Orleans | Git | Windows Services | CI/CD | Agile

What's on Offer

• £50,000 – £65,000 salary
• Competitive bonus scheme
• Hybrid working
• Company pension
• Increasing annual leave entitlement with length of service
• 24/7 GP access for you and your immediate family
• Enhanced maternity and paternity pay
• Employee Assistance Programme
• Wagestream financial wellbeing benefits
• Long-term career development within a technology-first organisation

Next Steps

If you're a .NET Developer who enjoys building scalable software, solving complex technical challenges and working on products used by millions of customers, we'd love to hear from you.

Apply today or get in touch with the MRJ team for a confidential conversation.