Security Engineer - Bristol (Hybrid) Security Clearance: SC (Eligible) DefStan NIST Threat ModellingAre you passionate about securing the future of critical technology? Do you have deep working knowledge of NIST standards and Defence Standards like DefStan 05-138 Issue 3 and DefStan 05-139 Issue 1?We''re hiring a Product Security Engineer to help shape the security architecture of next-generation defence and technology systems. This is a high-impact role where your expertise in threat modelling, risk assessment, and secure-by-design engineering will drive innovation and resilience from day one.What You''ll Be Doing:Leading product risk assessments and driving security improvements across the full development lifecycle.Conducting threat modelling and collaborating closely with engineers to embed security at every layer.Applying your hands-on knowledge of DefStan 05-138 and 05-139 to ensure products meet UK defence requirements.Leveraging the NIST 800 series (an absolute must) to establish best-in-class security frameworks.Performing code reviews, penetration testing, and guiding remediation efforts.Producing clear, robust documentation such as RMADS and Security Assurance artefacts.What You Bring:Proven experience with NIST 800-30, 800-37, 800-53 and related frameworks. (Essential)Practical, working knowledge of Defence Standards, especially DefStan 05-138 and DefStan 05-139.Familiarity with threat modelling tools and methodologies.Solid understanding of ISO 27001/2, ISO ..... full job details .....