R&D Software Engineer

About the role

FDM Group is seeking an R&D Software Engineer to join a Defence and Secure Technology client on a 6‑month contract with the possibility of extension. The role is hybrid, requiring two days per week on‑site in London, and focuses on early‑stage research, rapid prototyping and proof‑of‑concept delivery.

Key responsibilities

• Design and build rapid proof‑of‑concept applications in a secure development environment.
• Develop user‑focused solutions emphasizing usability and fast iteration.
• Extend an existing .NET‑based platform and distributed computing architecture.
• Integrate AI and machine‑learning models into prototype applications.
• Collaborate with architects, security specialists and product stakeholders throughout the lifecycle.
• Produce maintainable code and technical documentation.

Required profile

• Minimum 5 years of experience in software engineering, R&D or prototyping.
• Strong background in the Microsoft .NET ecosystem and modern C# development.
• Experience with distributed systems, actor‑based architectures or similar concepts.
• Proven ability to deliver rapid prototypes or proof‑of‑concept solutions.
• Interest in user‑centred design and secure, high‑trust environments.

Required skills

• .NET
• C#
• Distributed computing
• Actor‑based architectures
• Artificial Intelligence (AI)
• Machine learning

What we offer

• Competitive salary between £70,000 and £80,000 per year.
• Hybrid working model with two days on‑site.
• Opportunity to work on cutting‑edge defence technology and innovation projects.