C# Software Engineer Position Description At CGI, you''ll play a pivotal role in building and sustaining secure, high-impact applications that underpin critical services for our clients. As a C# Developer, you''ll 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, you''ll 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 you''ll be part of an open, friendly community of experts. We''ll 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 offic