Senior Developer (C#, ASP.NET MVC, JavaScript)

System C; Belfast City District; On-site; GBP 40,000 - 80,000; Full time

Job summary

System C is seeking a Senior Developer to design, build, and maintain software within the CIS Oncology (ChemoCare) product suite. You will own significant features from design through to testing and release, making technical trade‑offs and guiding the team toward robust, scalable solutions.

You will work across back‑end and front‑end layers, collaborating with QA to ensure quality and supporting more junior developers.

Qualifications

• Strong experience with C# and ASP.NET MVC.
• Strong SQL Server experience.
• Web development using JavaScript, HTML and CSS.
• Knowledge of mobile app deployment to Apple and Android stores.
• Experience using GitHub for source control and collaboration.
• Strong analytical and problem‑solving skills at strategic and tactical levels.
• Experience with complex or long‑lived codebases.
• Ability to make technical design decisions and manage trade‑offs.

Responsibilities

• Design, develop, and maintain software within the CIS Oncology (ChemoCare) product suite.
• Own complex features through design, implementation, and handover to testing and release.
• Make technical decisions and raise risks or trade‑offs as needed.
• Contribute to the technical direction balancing delivery with maintainability.
• Collaborate with QA to ensure quality and defect resolution.
• Ensure code is clear, well‑tested, and maintainable.
• Review code and provide constructive feedback.
• Support and mentor less experienced developers as part of the team.
• Provide 3rd line support as part of the shared team responsibility.

Skills

C#

ASP.NET MVC

JavaScript

HTML

CSS

React

React Native

TypeScript

NUnit

GitHub

Tools

SQL Server

GitHub

NUnit

Job description

Salary: £40,000 - 80,000 per year

Requirements

• Strong professional experience with C# and ASP.NET MVC


• Strong SQL Server experience


• Experience developing for the web using JavaScript, HTML, and CSS


• Knowledge of principles for writing mobile apps and deploying to Apple and Android app stores


• Experience using GitHub for source control and collaboration


• Strong analytical and problem-solving skills at both a strategic and tactical level


• Experience working with complex or long-lived codebases


• Confidence contributing to technical design and making informed trade-offs


• A pragmatic, calm approach when dealing with ambiguity or pressure


• Clear communication skills, including explaining technical constraints to non-technical stakeholders


• Significant commercial experience operating at senior developer level in both back-end and front-end areas


• Desirable: experience with React Native or React, or equivalent frameworks


• Desirable: experience writing automated unit tests using NUnit


• Desirable: good understanding of waterfall, agile, and scrum development methodologies and their practical application


• Desirable: experience in .NET 10 and other latest technologies including AI integration


• Desirable: experience in TypeScript

Responsibilities

• Design, develop, and maintain software within the CIS Oncology (ChemoCare) product suite


• Own complex features or technical areas through design, implementation, and handover into testing and release


• Make technical decisions and elevate risks or trade-offs where needed


• Contribute to the technical direction of the ChemoCare product suite, balancing near-term delivery with longer-term maintainability


• Work closely with the QA team to support effective testing, defect resolution, and overall product quality


• Ensure code is clear, maintainable, and appropriately tested in line with agreed development standards


• Review code written by others and provide practical, constructive feedback


• Support and mentor less experienced developers as part of normal team working


• Provide 3rd line support as part of a shared team responsibility, including investigation and resolution of complex defects where required

Technologies

• AI


• ASP.NET


• Android


• C#


• CSS


• GitHub


• Support


• JavaScript


• LESS


• Mobile


• MVC


• React


• React Native


• SQL


• Web


• TypeScript

More

We create technology that connects care and improves outcomes across the NHS. Our CIS Oncology (ChemoCare) product plays a critical role in supporting chemotherapy treatment management nationwide, and we continue to invest in its safety, quality, and long‑term evolution. This Senior Developer role sits within our CIS Oncology product suite and is a senior individual contributor position for an experienced hands‑on developer. You will work on software that genuinely matters, alongside people who value collaboration, ownership, and integrity. We support flexible working, encourage reflective practice, and value those who are comfortable navigating change while keeping quality and patient safety at the forefront.

last updated 33 week of 2026