C++ Software Engineer

World Class Defence Organisation based in Stevenage, Hertfordshire is currently looking to recruit a C++ Software Engineer subcontractor on an initial 12 month contract, with very likely extension. The role will be onsite 4 days per week. A 4 day working week is OK (Monday to Thursday).

Candidates with a strong C++ Software Engineering/Embedded Software Engineer background ideally from the Defence/Aerospace industry would be suitable for this position.

Rate: £67.00 per hour
Overtime Rate: Hours worked over the standard 37 hours per week, will be paid at 'time and a quarter'
Location: Stevenage
Hybrid/Remote working: The role will be onsite 4 days per week. A 4 day working week is OK (Monday to Thursday).
Duration: 12 Months with very likely extension. Contracts are often ongoing and long-term thereafter.
IR35 status: Inside IR35 (Umbrella)
Interview process: One stage video interview

Job Description:
By embracing the latest software technologies and methods the Development Simulation software department delivers exceptional software solutions for non-production based test systems that meet the unique requirements of the prime software development teams. In addition we also provide equipment simulation systems to support product integration as well as software to support and assist the manufacturing process.
The successful candidate will join the development team responsible for building and integrating Real Time test and data capture systems. The role will focus on developing and maintaining software in a Linux environment, working closely with high-speed multi-channel SFPDP cards, Real Time data flows, and complex multi-threaded processing pipelines.
Proficient in C++ and with knowledge of C#, you will play a critical part in the design, development, integration, and verification of test software solutions that are central to our system validation and delivery capabilities.

Responsibilities:

• Design and develop Real Time test and capture software on Linux systems using C++.
• Integrate and interface with high-speed SFPDP cards across multi-channel data pipelines.
• Architect and implement robust, scalable, and maintainable multi-threaded applications.
• Define and implement data sequencing and synchronisation logic to support deterministic capture and replay.
• Work with hardware teams to ensure seamless integration and timing alignment between software and capture cards.
• Lead and contribute to system integration, verification, and testing at both component and system levels.
• Conduct performance analysis, debugging, and optimisation of Real Time systems.
• Document architecture, interface definitions, and test procedures to support handover and formal test activities.

• Extensive experience in C++ development in a Linux environment.
• Proficiency in C# for tooling, test interfaces, or Windows components as needed.
• Proven experience working with Real Time data systems, preferably involving SFPDP or other high-speed digital protocols.
• Demonstrable skills in multi-threaded and concurrent programming.
• Experience with low-level I/O, DMA, or driver-level interactions with PCIe cards or similar.
• Familiarity with software sequencing frameworks or custom state machines for test execution.
• Strong experience with integration, system test, and debugging complex interactions between software and hardware.
• Strong understanding of software design principles, memory management, and performance optimisation.
• Experience with version control systems (eg, Git) and CI/CD

• Experience with SFPDP (Serial Front Panel Data Port) specifically in defence, aerospace, or data acquisition contexts.
• Knowledge of FPGA-based data acquisition systems and synchronisation methods.
• Familiarity with unit testing frameworks, automated test rigs, or hardware-in-the-loop (HWIL) setups.
• Experience developing or integrating with Real Time operating systems (RTOS) or using Real Time Linux extensions.