Senior .NET Backend Developer

Location: York (Hybrid - 2 days per week)
Salary: Competitive + Benefits

We're partnering with an established technology business undergoing a significant platform modernisation programme and are looking to appoint a Senior .NET Backend Developer to play a key role in shaping the future of its engineering capability.

This is a hands-on senior engineering position, working closely with product and engineering teams, you'll help drive technical direction, champion best practice and contribute to the evolution of a high-performing development function.

The Role

• Design, develop and maintain backend services and APIs using C# and modern .NET / ASP.NET Core.
• Contribute to architectural decisions across backend services, integrations and data.
• Modernise legacy applications into scalable, maintainable web-based solutions.
• Collaborate with cross-functional teams to deliver robust technical solutions.
• Promote engineering best practices, including automated testing, code quality and security.
• Investigate and resolve complex production issues.
• Support technical leadership through mentoring, knowledge sharing and architectural guidance.

Required Experience

• Commercial experience with C#, .NET and ASP.NET Core.
• Strong background developing scalable APIs and backend services.
• Experience designing software architecture and distributed systems.
• Solid SQL and relational database knowledge.
• Strong understanding of software design principles, dependency injection and automated testing.
• Experience working on complex or legacy software modernisation projects.
• Excellent communication skills with the ability to influence technical decisions.

Desirable Skills

• Docker and Kubernetes.
• PostgreSQL, Redis or Elasticsearch.
• GraphQL.
• RabbitMQ or other messaging technologies.
• CI/CD pipelines and modern DevOps practices.
• Observability tooling such as Grafana, OpenTelemetry or Prometheus.
• Experience using AI-assisted development tools within the software development lifecycle.

What's on Offer

• Hybrid working (2 days per week in York).
• Flexible working hours.
• Opportunity to influence architecture and technical strategy.
• Modern technology environment with investment in engineering tooling.
• Excellent benefits package.

Oscar Associates (UK) Limited is acting as an Employment Agency in relation to this vacancy.

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