Senior C++ Software Engineer

ALTEN is a global engineering and technology consultancy operating across over 35 countries worldwide. We partner with industry leaders across sectors including Aeronautics, Aerospace, Defence, Naval, Automotive, Energy, Rail, IT and many more to deliver innovative engineering solutions that drive technological advancement & support sustainable transformation.

Our teams of passionate and agile engineers work on cutting-edge projects that shape the future of technology and sustainability. At ALTEN, we empower talented engineers to innovate, solve complex challenges, and deliver impactful solutions that build tomorrow’s world—today.

Join us and start building tomorrow’s world today!

Join our team to deliver high-impact Defence software solutions for mission-critical systems. You’ll work on projects requiring robust, safety-regulated software development, applying your expertise in C++ and compliance standards to ensure reliability and security. This is an opportunity to contribute to fast-paced defence programmes, where your work directly supports operational capability.

Location: London (EC2)

On-site: Hybrid (3 days per week)

Seniority: Senior (8+ years of experience) 

Clearance: Candidates must be willing and eligible to obtain SC clearance.

Key Responsibilities

• Design, develop, and maintain C++ software for mission-critical defence systems.
• Apply DO-178 principles and ensure compliance with safety standards.
• Perform black-box/system-level testing and verification activities.
• Collaborate with multi-disciplinary teams to integrate software into complex systems.
• Support configuration management and CI/CD processes (Git, Jenkins, CMake).
• Produce clear technical documentation aligned with regulated environments.

Required Skills

• 8+ years of proven experience in C++ (modern standards: C++11/14/17/20).
• Knowledge of DO-178 processes and safety-critical development.
• Experience with black-box testing, verification, and requirements traceability.
• Familiarity with configuration management and build tools (Git, Jenkins, CMake).
• Understanding of coding standards (e.g., MISRA, CERT C++).

Soft Skills & Collaboration

• Excellent communication skills for cross-functional collaboration.
• Strong problem-solving and adaptability in regulated environments.
• Ability to work effectively in multi-disciplinary teams.
• Proactive approach to continuous improvement and quality assurance.

Required Qualifications

• Bachelor’s or Master’s degree in Software Engineering, Computer Science, or related discipline or  relevant technical military background with equivalent experience.
• Must be eligible to hold or already hold UK SC Security Clearance. 

Desirable Skills

• Exposure to RTOS, Linux, or embedded systems.
• Knowledge of ADA programming language in embedded systems
• Familiarity with requirements tools (e.g., DOORS).
• Background in defence, aerospace, or safety-critical domains.

Why join us? 

We bring together entrepreneurial, tech-driven people to deliver innovative solutions for leading companies.

At ALTEN, you’ll work on exciting projects, supported by ongoing learning, mentoring, and clear career development tailored to your goals.

Join a passionate team and help build tomorrow, today.

In short you get: 

• A personalised career path and a rewarding management style 
• A huge diversity of engineering projects and industries
• Private Medical Insurance
• Cycle & Tech Scheme 
• Employee assistance programme
• Life insurance & Pension Scheme
• Social atmosphere, regular gatherings & team buildings
• Flexible way of working (role dependent)

We are proud to support the Armed Forces Covenant & actively encourage applications from members of the Armed Forces community, including veterans, reservists, service leavers, and military spouses/partners. We recognise the value of military skills and experience and are committed to ensuring that no applicant is unfairly disadvantaged during our recruitment and selection processes. 

ALTEN is committed to fostering a diverse and inclusive workplace and values the strength that comes from a global mix of backgrounds and perspectives. We welcome applications from all suitably qualified candidates, regardless of background or protected characteristics under the Equality Act 2010. If you require any reasonable adjustments during the recruitment process, please let us know. 

This role may require you to have or be willing to go through Security Clearance. As part of the onboarding process candidates will be asked to complete a Baseline Personnel Security Standard; details of the evidence required to apply may be found on the government website Gov.UK. If you are unable to meet this and any associated criteria, then your employment may be delayed, or rejected . Details of this will be discussed with you at interview.