Security Assurance Engineer – Defence

Affinity Talent Partners; Southampton; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Hybrid working

Private healthcare

Strong pension

Enhanced leave

Job summary

Affinity Talent Partners is seeking a senior security architect to lead the security workstream for a complex, MoD-facing defence system. You’ll own the security case, produce accreditation artefacts such as RMADS and Secure by Design artefacts, and collaborate directly with MoD stakeholders and systems engineers.

You’ll operate with genuine influence on design decisions, enjoy long‑term funded work, and benefit from a hybrid working model, professional development support, and a competitive

Qualifications

• Experience delivering security accreditation or assurance for MoD/defence systems.
• Knowledge of Secure by Design, JSP 440 and Defstan 05-138.
• Current SC clearance or clear eligibility (DV advantageous).
• Engineering or systems background rather than enterprise IT.

Responsibilities

• Lead the security workstream for a complex, safety- and mission-critical communications system.
• Develop and maintain the security case and accreditation artefacts.
• Work directly with MoD stakeholders and systems engineers to embed security in design.
• Produce RMADS and other accreditation artefacts.
• Directly influence design decisions with the customer.

Skills

Security architecture

Defence MoD systems

Secure by Design

JSP 440

Defstan 05-138

SC clearance (DV advantageous)

Tools

RMADS

JSP 440

Defstan 05-138

Job description

We're recruiting on behalf of an established defence technology company delivering into a major, long-term UK MoD programme — one with funded work stretching well into the next decade. This is a retained, exclusive assignment.

This is a role with genuine ownership: you'll lead the security workstream for a complex, safety- and mission-critical communications system — developing and maintaining the security case, producing accreditation artefacts (RMADS / Secure by Design), and working directly with MoD stakeholders and systems engineers to keep security embedded in design rather than bolted on afterwards. Your work will be visible at programme level, not buried three layers down in a security function.

Why this role:

• Ownership, not a cog — you're the security authority on the system, with direct access to the customer and real influence over design decisions
• Programme stability — long-term funded work, not a contract that evaporates at the next spending review
• Career development — support for professional certifications and CIISEC/chartership progression, with a clear route into senior security architecture
• Genuine flexibility — hybrid working that's actually honoured, not a return-to-office policy in disguise
• Package — competitive salary, strong pension, private healthcare and enhanced leave

You'll likely have experience delivering security accreditation or assurance for MoD or defence systems — you'll know your way around Secure by Design, JSP 440 and Defstan 05-138 — with a systems or engineering-leaning background rather than enterprise IT or protective security. Current SC clearance or clear eligibility (DV an advantage).

South of England. If real engineering security work with real influence appeals — get in touch or apply with your CV.