Software Design Engineer (DO178C)

Expleo is seeking an experienced Software Design Engineer (DO178C) to support a major DAL D to DAL A software assurance uplift programme. The role is responsible for reconstructing Low-Level Requirements (LLRs) from an existing embedded software baseline, architectural artefacts and SysML models, creating the design evidence required to satisfy DAL A objectives. Working alongside requirements, certification and verification specialists, the successful candidate will transform an existing DAL D implementation into a fully traceable DAL A design baseline. This role sits directly on the programme critical path, as the RFQ confirms that no formal LLR set currently exists for much of the software baseline. This role is based full-time on-site, working directly alongside customer engineering and assurance teams throughout programme execution. Responsibilities:

• Develop and maintain Low-Level Requirements (LLRs) from existing architecture, design models and software implementation.
• Analyse source code, design artefacts and system models to derive accurate design-level requirements.
• Ensure alignment between HLRs, LLRs, architecture and implementation.
• Establish and maintain design traceability within the programme requirements management environment.
• Support architectural design updates for in-scope functionality including ARINC and CAN capabilities.
• Identify design inconsistencies, omissions and compliance gaps.
• Work with Requirements Engineers to ensure requirement decomposition is complete and auditable.
• Support formal design reviews and independent assurance activities.
• Produce design rationale and supporting review evidence.
• Support implementation reviews against derived design intent.
• Provide technical support to verification and certification teams.
• Contribute to compliance matrices, design metrics and certification evidence production.
• Support issue resolution arising from verification, static analysis and review activities., + Ensure our recruitment process is inclusive and accessible
• Communicating and promoting vacancies
• Offering an interview to disabled people who meet the minimum criteria for the job
• Anticipating and providing reasonable adjustments as required
• Supporting any existing employee who acquires a disability or long term health condition, enabling them to stay in work at least one activity that will make a difference for disabled people

• Degree qualified in Software Engineering, Electronic Engineering, Computer Science, Systems Engineering or related discipline.
• Embedded software or real-time systems engineering background preferred.
• Exposure to safety-critical software development standards is desirable.

Essential skills:

• Embedded software design and software architecture principles.
• Creation and maintenance of Low-Level Requirements (LLRs).
• Experience translating software implementation into structured design artefacts.
• Strong requirements decomposition and traceability skills.
• Understanding of design-to-code and code-to-design relationships.
• Experience reviewing embedded software implementations.
• Strong analytical problem-solving capabilities.
• Ability to understand and interpret complex software architectures.
• Experience supporting formal technical review processes.
• Excellent written communication and technical documentation skills.

Desired skills:

• DO-178C software lifecycle knowledge.
• Experience deriving LLRs to support DAL A or DAL B compliance activities.
• STM32 microcontroller experience.
• Ada, C and/or C++ development experience.
• SysML and Cameo Systems Modeler experience.
• Knowledge of driver, BSP and platform software architectures.
• Experience within aerospace, defence or other safety-critical industries.
• Familiarity with Polarion, BitBucket and software configuration management processes.
• Understanding of verification, structural coverage and certification evidence generation.

Experience:

• Experience developing or reconstructing software design artefacts for embedded systems.
• Experience supporting safety-critical or regulated software development programmes.
• Demonstrable experience establishing traceability between requirements, design and implementation.
• Experience reviewing and interpreting existing software baselines.
• Experience participating in formal design reviews and compliance assessments.
• Experience working within multidisciplinary engineering and assurance teams.

• Collaborative working environment - we stand shoulder to shoulder with our clients and our peers through good times and challenges
• We empower all passionate technology loving professionals by allowing them to expand their skills and take part in inspiring projects
• Expleo Academy - enables you to acquire and develop the right skills by delivering a suite of accredited training courses
• Competitive company benefits
• Always working as one team, our people are not afraid to think big and challenge the status quo