Senior .NET Developer | Application Modernisation

• Approx. 6-month contract from 5 October 2026 to 9 April 2027
• Work on a major government application modernisation program
• 2 Senior .NET Developer positions available

About the Role

Green Light Worldwide is seeking two Senior .NET Developers to support a major application modernisation program within a large government technology environment.

The successful candidates will work across the full software development lifecycle, contributing to requirements analysis, solution design, development, testing, deployment and ongoing application improvement.

The environment includes both modern and legacy Microsoft technologies, so candidates will need strong hands-on experience across C#, .NET Framework, .NET Core/.NET, ASP.NET and web application development, together with the ability to maintain and enhance established enterprise applications.

Responsibilities

• Participate in requirements analysis and translate requirements into technical solutions.
• Collaborate with internal teams to develop software designs and application architecture.
• Develop clean, scalable and maintainable applications using Microsoft .NET technologies.
• Maintain, enhance and refactor existing enterprise applications.
• Test, troubleshoot, debug and deploy applications and systems.
• Contribute to improvements across existing software solutions.
• Develop and maintain technical documentation throughout the software development lifecycle.
• Support applications through development, production deployment and early-life support.
• Contribute to application design, development practices and team ways of working.
• Provide technical expertise and application support where required.

Requirements

• 8–10+ years' overall software development experience.
• 5+ years' deep hands-on .NET development experience, including:
  • C#
  • .NET Framework
  • .NET Core / .NET
  • ASP.NET
• Experience developing web-based applications using the Microsoft .NET stack.
• Demonstrated experience maintaining and enhancing legacy ASP.NET applications, including exposure to:
  • C#
  • .NET Framework 4.0
  • Visual Studio 2010
  • Oracle database integration
  • NUnit
• Experience with Microsoft technologies including ASP.NET, VB.NET, Web API, WCF, ASP.NET MVC and Microsoft SQL Server.
• Experience with at least one modern web technology such as AngularJS, JavaScript, Angular or React.
• Experience with UI/UX development within web applications.
• Strong understanding of application design and architectural patterns, including Model-View-Controller (MVC).
• Familiarity with API and architectural styles including REST and RPC.
• Strong experience with DevOps practices and continuous integration, delivery and deployment pipelines (CI/CD).
• Experience implementing automated testing practices.
• Strong commitment to code ownership throughout the application lifecycle, from development through production deployment and support.
• Experience working within Agile / Scrum delivery environments.
• Excellent troubleshooting, communication and problem-solving skills.
• Ability to contribute effectively within a highly collaborative and interactive development team.
• Strong attention to detail.
• Ability to successfully complete the required Police Integrity Check.