We are seeking an experienced Senior .NET and Azure Engineer to join our engineering team on a contract basis. This role is suited to a hands-on engineer who can quickly understand a large, business-critical platform, contribute with minimal ramp-up time, and work effectively across legacy .NET systems, cloud migration initiatives, integrations, test automation, and production support. The successful contractor will be comfortable working in a mature and complex technology environment while helping improve reliability, maintainability, test coverage, performance, and delivery efficiency. ### Key Responsibilities - Design, develop, test, and maintain applications built with C# and the .NET Framework. - Deliver enhancements and fixes across ASP.NET MVC, Web API, Windows Services, WCF, messaging, database, and integration components. - Support the ongoing migration of systems and workloads to Microsoft Azure. - Contribute to architectural and technical decisions relating to cloud migration, application modernization, observability, scalability, and resilience. - Work with RavenDB, SQL Server, Redis, MSMQ, and custom data replication processes. - Build and maintain integrations with third-party systems, including ERP platforms, SFTP/FTP feeds, email ingestion services, and SOAP APIs. - Support document-processing and OCR workflows using LEADTOOLS and Azure Document Intelligence. - Improve automated test coverage across unit, integration, end-to-end, regression, and performance testing. - Maintain and extend test suites using NUnit, Selenium, SpecFlow, and Playwright. - Diagnose production issues using application logs, telemetry, performance monitoring, and distributed system analysis. - Contribute to Azure DevOps repositories, build pipelines, deployment processes, and internal NuGet packages. - Work closely with developers, testers, product stakeholders, and operational teams to deliver changes safely and efficiently. - Review existing code, identify technical risks, and propose pragmatic improvements. - Use AI-assisted development tools effectively to accelerate analysis, implementation, testing, documentation, and troubleshooting while maintaining engineering quality. - Produce clear technical documentation and communicate progress, risks, and dependencies proactively. - Provision and configure production-like environments in Azure; including compute, networking, and the RavenDB/SQL Server/Redis/MSMQ tiers, to support performance testing, load reproduction, and lift-and-shift piloting. ### Required Skills and Experience - Strong commercial experience developing applications in C# and .NET Framework. - Strong experience with Microsoft Azure and cloud migration projects. - Experience working with ASP.NET MVC 5 and ASP.NET Web API 2. - Experience developing or supporting Windows Services. - Strong understanding of enterprise application architecture, distributed systems, and integration patterns. - Experience with automated testing, including end-to-end or acceptance testing. - Hands-on experience with NUnit, Selenium, SpecFlow, or Playwright. - Strong SQL skills and commercial experience with Microsoft SQL Server. - Experience working with document databases or NoSQL platforms; RavenDB experience is highly desirable. - Experience with messaging technologies such as MSMQ or equivalent asynchronous messaging platforms. - Experience diagnosing production defects and performance issues in complex systems. - Familiarity with CI/CD processes using Azure DevOps, MSBuild, or VSBuild. - Ability to work effectively with an established codebase containing legacy and modern components. - Ability to become productive quickly with limited supervision. - Strong problem-solving, debugging, and analytical skills. - Clear written and verbal communication. - A pragmatic, delivery-focused approach with strong attention to quality. ### Highly Desirable Experience - RavenDB 6.x, including: - Document modelling - Per-customer database architectures - Lucene indexing - Query and index performance optimisation