C# Software Engineer

Position Description:

At CGI youll play a pivotal role in building and sustaining secure high-impact applications that underpin critical services for our clients. As a C# Developer youll contribute to the full application lifecycle combining hands-on development with 4th line support to ensure resilient high-performing systems. Working within a collaborative ownership-driven culture youll help deliver measurable outcomes strengthen long-term client relationships and shape solutions that make a real difference in a highly secure environment.

CGI was recognised in the Sunday Times Best Places to Work List 2025 and has been named a UK Best Employer by the Financial Times. We offer a competitive salary excellent pension private healthcare plus a share scheme (3.5% 3.5% matching) which makes you a CGI Partner not just an employee. We are committed to inclusivity building a genuinely diverse community of tech talent and inspiring everyone to pursue careers in our sector including our Armed Forces and are proud to hold a Gold Award in recognition of our support of the Armed Forces Corporate Covenant. Join us and youll be part of an open friendly community of experts. Well train and support you in taking your career wherever you want it to go.

Due to the secure nature of the programme you will need to hold UK Security Clearance or be eligible to go through this clearance. This is a full-time onsite position based in our Reading office five days per sole nationality is required.

Your future duties and responsibilities:

In this role you will develop maintain and support a secure application using C# and SQL Server taking ownership of both new functionality and the stability of a mature system. Youll work closely with colleagues and where appropriate directly with the client building trust through clear technical communication and reliable delivery. Supported by experienced peers youll grow into a trusted technical authority and subject matter expert for the customer environment.

You will contribute to continuous improvement by applying strong software development practices diagnosing complex issues and ensuring solutions meet the highest security and quality standards.

Key responsibilities include:

- Develop & enhance secure applications using C# and

- Support & resolve complex 4th line application issues

- Analyse debug and improve mature production systems

- Manage code and work items using Azure DevOps

- Collaborate with stakeholders and communicate technical solutions clearly

- Contribute to best practice within a highly secure delivery environment

Required qualifications to be successful in this role:

You will bring solid experience in Microsoft-based application development with the ability to support and enhance secure business-critical systems. You should be comfortable working with established codebases applying strong debugging skills and communicating effectively with both technical and non-technical stakeholders.

Essential qualifications:

- Strong experience with C# and

- Proven experience using SQL Server

- Familiarity with the Microsoft development toolchain

- Good understanding of modern software development practices

- Experience supporting and debugging mature applications

- Ability to work effectively in a secure environment

- Clear and confident technical communication skills


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Skills:

• C#
• SQLite
• Web Development

What you can expect from us:

Together as owners lets turn meaningful insights into action.

Life at CGI is rooted in ownership teamwork respect and belonging. Here youll reach your full potential because

You are invited to be an owner from day 1 as we work together to bring our Dream to life. Thats why we call ourselves CGI Partners rather than employees. We benefit from our collective success and actively shape our companys strategy and direction.

Your work creates value. Youll develop innovative solutions and build relationships with teammates and clients while accessing global capabilities to scale your ideas embrace new opportunities and benefit from expansive industry and technology expertise.

Youll shape your career by joining a company built to grow and last. Youll be supported by leaders who care about your health and well-being and provide you with opportunities to deepen your skills and broaden your horizons.

Come join our teamone of the largest IT and business consulting services firms in the world.