Job Title: Senior C# EngineerLocation: RuncornSalary: Competitive (based on experience)Working Pattern: Full-time, Permanent About Us:PHOENIX Medical Supplies is a leading provider of healthcare and pharmaceutical distribution services across the UK. Our Digital Technology department is at the heart of our innovation, driving the development and modernisation of key systems that support our customers and business operations.We're now seeking a Senior C# Engineer to play a pivotal role in maintaining, enhancing, and evolving our internal middleware applications — the Phoenix Data Integrator and IM1g — which connect our core systems and support services such as Hey Pharmacist. This is a key position for an experienced engineer looking to shape the technical direction of critical digital infrastructure. Key Responsibilities:Lead the design, development, and maintenance of APIs and integration components using C# and related technologies.Drive system modernisation and tackle technical debt through refactoring and continuous improvement.Ensure all development aligns with best practices, coding standards, and SOLID design principles.Collaborate with project stakeholders, QA, and DevOps teams to deliver high-quality, secure, and scalable solutions.Identify and resolve performance bottlenecks, build issues, and deployment challenges.Lead code reviews, mentor junior developers, and promote team-wide technical excellence.Support automated testing and CI/CD pipeline improvements.Contribute to ongoing improvements in processes, tooling, and development practices. What We're Looking For:Extensive experience as a Senior C# Engineer, with deep understanding of .NET Framework 4.8 and .NET Core.Strong experience with JSON, XML, XSD, and XSLT.Proficiency with SQL Server (2019) and strong understanding of performance optimisation.Skilled in unit testing and Test-Driven Development (TDD) using tools such as NUnit.Proven experience deploying applications to IIS and troubleshooting complex build or release issues.Excellent communication skills with the ability to collaborate across teams and mentor others.Desirable:Experience with WCF, ServiceStack, or Developer Express.Experience working with Azure DevOps, CI/CD pipelines, or Azure App Service.Knowledge of legacy system maintenance and modernisation.Familiarity with AWS and cloud migration projects. What We Offer:25 days (pro rata) annual leave plus bank holidays, increasing with length of serviceMedicash – a health cash plan to support everyday healthcare costs (e.g. eyecare, prescriptions)iTrent Financial Wellbeing – an app to help manage and access your pay flexiblyHigh street discounts and offersEmployee Assistance Programme (EAP)Contributory Pension SchemeFully funded accredited training programmes through the Apprenticeship SchemeINDPMS