Software Engineer

Role: Senior C++ Software Engineer

Location: UK – Hybrid (key defence hub)

Salary: £45,000 – £65,000 depending on experience, plus bonus and benefits

A leading organisation in the UK defence and national security sector is expanding its software engineering function and is seeking an experienced C++ Software Engineer to help build, evolve and support mission‑critical wireless intelligence and security products. This role offers the chance to work on cutting‑edge systems used directly by international defence customers, while developing your expertise within a highly technical, collaborative environment.

The role

As a C++ Software Engineer, you’ll be at the centre of designing, developing and optimising high‑performance software on Linux for advanced wireless and networking systems. You’ll work across the full product lifecycle – from rapid prototyping and proof‑of‑concept work through to deployment, in‑service support and continuous improvement of complex national security platforms. Working closely with fellow engineers, product and operational teams, you’ll ensure systems are robust, scalable and reliable in demanding real‑world environments.

You’ll also have the opportunity to visit international customer sites a few times a year to see your products in use, gather feedback first‑hand and help troubleshoot live deployments. If you enjoy combining hands‑on coding with real operational impact, this C++ Software Engineer position will give you that visibility.

What you’ll be doing

• Designing, developing and maintaining modern C++ software on Linux for high‑throughput wireless and networking products.
• Applying concurrency and performance‑tuning techniques to handle large volumes of network traffic efficiently.
• Working with TCP/IP and higher‑level protocols (such as HTTP, DNS, DHCP and tunnelling protocols) to implement deep packet inspection and analysis features.
• Integrating third‑party and open‑source components (e.g. Boost) and contributing to internal libraries and frameworks.
• Participating in agile Scrum teams: refining user stories, estimating work, and delivering increments through regular sprints.
• Using Linux build systems, compilers and tooling to debug complex issues, including those involving kernel and driver interactions.
• Remotely diagnosing and troubleshooting systems in the field, working alongside in‑country support staff and end users.
• Supporting rapid prototyping activities to prove new capabilities quickly, then hardening successful prototypes into production‑ready software.

In this C++ Software Engineer role you’ll be expected to take ownership of features, contribute ideas for technical improvements and help uplift team practices over time.

What we’re looking for

• Strong commercial experience in C++ development, including modern standards (e.g. C++11/14/17), with a focus on performance and concurrency.
• Solid background in Linux development – comfortable with build systems, tools, compilers and working close to the operating system.
• Good understanding of computer networking and TCP/IP, ideally with exposure to protocols such as HTTP, DNS, DHCP or tunnelling protocols (GTP, MPLS, L2TP).
• Experience working in agile Scrum teams, using tools such as Jira to manage and deliver work.
• Proven ability to remotely diagnose and troubleshoot complex distributed or networked systems.
• Strong communication skills and the confidence to work with international customers, operations and support staff.
• Willingness to travel internationally a few times per year to visit deployed systems.
• Eligibility for UK security clearance and the ability to meet residency requirements.

What’s on offer

• Competitive salary from £55,000 depending on experience, plus annual performance bonus.
• Comprehensive pension and benefits package, including private healthcare and wellbeing perks.
• Hybrid and flexible working arrangements within a leading defence and national security organisation.
• Opportunities for career development, cross‑training and progression within a high‑performing engineering community.

Due to the nature of the work, candidates must be eligible for UK security clearance and able to meet associated nationality and residency requirements.

Want to hear more? Make an application, lets have a chat!