Senior C# Developer

Phoenix Medical Supplies; Runcorn; On-site; GBP 80,000 - 100,000; Full time

Job summary

A leading healthcare distribution provider in the UK seeks a Senior C# Engineer to enhance internal middleware applications. This full-time position involves leading API development and ensuring system performance using .NET technologies. Candidates must demonstrate strong experience in C#, SQL Server, and effective collaboration skills. The role offers a competitive salary and a variety of employee benefits including health cash plans and professional development opportunities.

Benefits

25 days annual leave plus bank holidays

Health cash plan

iTrent Financial Wellbeing app

High street discounts

Employee Assistance Programme

Contributory Pension Scheme

Fully funded accredited training programmes

Qualifications

• Extensive experience as a Senior C# Engineer required.
• Strong understanding of .NET Framework and .NET Core.
• Proficiency with SQL Server and performance optimisation skills.

Responsibilities

• Lead design, development, and maintenance of APIs and integration components using C#.
• Drive system modernization and address technical debt.
• Ensure development aligns with best practices and coding standards.
• Collaborate with teams to deliver secure and scalable solutions.
• Identify and resolve performance bottlenecks.

Skills

Senior C# Engineer experience

.NET Framework 4.8+

.NET Core

JSON

XML

SQL Server

NUnit

IIS deployment

Performance optimisation

Communication skills

Tools

Azure DevOps

CI/CD pipelines

AWS

Job description

Job Title: Senior C# Engineer
Location: Runcorn
Salary: 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 service
• ash – 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 flexibly
• High street discounts and offers
• Employee Assistance Programme (EAP)
• Contributory Pension Scheme
• Fully funded accredited training programmes through the Apprenticeship Scheme