Principal System Engineer

Principal Systems Engineer – Systems Architecture
£78.33 per hour (Inside IR35)
Mostly remote - 1-2 days per fortnight, lake District, Bristol, Portsmouth, Coventry.
Must be eligible for UK Security Clearance (SC), with the ability to obtain higher levels of clearance if required
We are seeking an experienced Principal Systems Engineer – Systems Architecture to join a growing engineering team delivering complex, mission-critical solutions within the UK Defence sector.
This is a senior technical leadership role responsible for defining, developing, and governing system architectures across the full engineering lifecycle. You will work closely with customers, stakeholders, and multidisciplinary engineering teams to ensure solutions meet demanding operational, performance, safety, and security requirements.
The successful candidate will combine strong systems engineering expertise with strategic architectural thinking, helping to shape future defence capabilities and influence major programme decisions.
Key Responsibilities
Lead the development and maintenance of system architectures for complex defence systems.
Define system requirements, operational concepts, and architectural frameworks.
Conduct trade studies, option analyses, and technology assessments.
Manage system-level design activities throughout the engineering lifecycle.
Ensure compliance with customer, regulatory, and defence standards.
Develop architectural artefacts using industry-recognised frameworks and modelling techniques.
Support requirements management, verification, validation, and acceptance activities.
Provide technical leadership and mentoring to systems engineers and architects.
Engage with customers, suppliers, and external stakeholders to influence technical direction.
Contribute to bids, proposals, and future capability development initiatives.
Essential Skills & Experience
Degree-qualified in Engineering, Physics, Mathematics, Computer Science, or a related discipline.
Significant experience in systems engineering within the defence, aerospace, maritime, or highly regulated sectors.
Proven experience developing and managing complex system architectures.
Strong understanding of the systems engineering lifecycle and V-model processes.
Experience with requirements management and systems modelling tools.
Knowledge of architectural frameworks such as MODAF, NAF, TOGAF, or equivalent.
Experience applying Model-Based Systems Engineering (MBSE) principles.
Excellent stakeholder management and communication skills.
Ability to lead technical reviews and make evidence-based engineering decisions.
Desirable Experience
Chartered Engineer (CEng) status or working towards accreditation.
Experience with digital engineering environments and MBSE tools such as Cameo Systems Modeler, Enterprise Architect, or Sparx EA.
Knowledge of defence standards, safety engineering, cyber security, and mission systems.
Experience across land, maritime, air, or space defence programmes.
Understanding of system integration and complex system-of-systems architectures.

Work arrangement
Yes