Senior Software Engineer

Expleo is seeking Software Engineers to join our growing Belfast team, delivering high-integrity engineering solutions across a range of complex and safety-critical domains. This role is ideally suited to candidates with experience in safety-critical or defence environments, though we also welcome strong software engineers from non-safety-critical backgrounds who are motivated to transition into this space through structured training and mentorship.

Responsibilities

• As a Software Engineer at Expleo, you will work on the design, development, testing, and integration of software systems used in regulated and high-assurance environments.
• You will contribute to the delivery of robust, secure, and reliable software solutions, often within defence, aerospace, or other safety-critical industries.
• While prior safety-critical experience is highly desirable, we provide comprehensive training and support for engineers looking to develop expertise in standards-driven development environments.
• Design, implement, and test high-quality software solutions in line with project and regulatory requirements
• Work within structured development processes (e.g. requirements traceability, verification & validation)
• Collaborate with systems engineers, test engineers, and stakeholders across multidisciplinary teams
• Contribute to software design documentation and technical specifications
• Participate in code reviews and support continuous improvement of engineering practices
• Ensure compliance with relevant safety, security, and quality standards where applicable
• Support integration and validation activities in lab or simulated environments

Qualifications

Candidates without direct safety-critical experience are encouraged to apply. Expleo provides:

• Structured onboarding into safety-critical engineering practices
• Training in relevant industry standards and compliance processes
• Mentorship from experienced engineers within regulated domains
• Opportunities to work on progressively complex and high-assurance systems

Essential skills

• Strong understanding of software engineering principles and lifecycle development
• Good problem-solving skills and attention to detail
• Ability to work effectively within a team and communicate technical concepts clearly

Desired skills

• Background in safety-critical, defence, aerospace, automotive, rail, or other regulated industries
• Familiarity with standards such as DO-178C, ISO 26262, IEC 61508, or similar
• Knowledge of embedded systems or real-time software development

Experience

• Background in safety-critical, defence, aerospace, automotive, rail, or other regulated industries
• Familiarity with standards such as DO-178C, ISO 26262, IEC 61508, or similar
• Experience with requirements management and traceability tools
• Knowledge of embedded systems or real-time software development
• Experience with configuration management tools (e.g. Git, SVN)
• Experience in software development using languages such as C, C++, Java, or similar
• Experience working in structured development environments (Agile, V-Model, or similar)