Job Description

Product Security Engineer
Hybrid - 3 Days a week in the Office
Bristol Based
This role blends secure-by-design engineering and security assurance to safeguard mission-critical products operating in complex and demanding environments.
You will act as a technical security authority, collaborating across software, systems, and hardware teams to embed robust security controls, while also representing the organisation to the UK Ministry of Defence (MoD) and other regulatory bodies to demonstrate compliance with stringent security and airworthiness standards.
Key Responsibilities

• Lead product-level cybersecurity assessments for UAV platforms, avionics, and embedded payload systems.
• Conduct vulnerability analysis and assurance activities across software, firmware, and communication interfaces.
• Develop and maintain product security architectures, ensuring compliance with secure-by-design principles and recognised standards.
• Support and participate in MoD and customer assurance reviews, presenting evidence of product robustness, testing outcomes, and mitigation strategies.
• Produce and maintain security documentation including Security Cases, and risk assessments for submission to accrediting authorities.
• Perform design assurance testing and verification in alignment with standards such as Secure by Design and NIST.
• Contribute to security certification efforts, providing technical input during formal reviews, audits, and design sign-offs.
• Collaborate with systems and software teams to implement Secure Development Lifecycle (SDL) processes.
• Identify and mitigate cyber threats early in the product lifecycle through threat modelling and risk analysis.
• Drive continuous improvement in security testing, automation, and vulnerability management practices.
• Proficiency in one or more programming/scripting languages: C, C++, Python, or Bash, preferably in embedded or Linux environments.
• Familiarity with relevant standards, including:

o DEF STAN 05-138 - Cyber Security in Defence Acquisition
o DO-326A / ED-202A - Airworthiness Security
o ISO/SAE 21434 - Automotive Cybersecurity
Modis International Ltd acts as an employment agency for permanent recruitment and an employment business for the supply of temporary workers in the UK. Modis Europe Ltd provide a variety of international solutions that connect clients to the best talent in the world. For all positions based in Switzerland, Modis Europe Ltd works with its licensed Swiss partner Accurity GmbH to ensure that candidate applications are handled in accordance with Swiss law.
Both Modis International Ltd and Modis Europe Ltd are Equal Opportunities Employers.
By applying for this role your details will be submitted to Modis International Ltd and/ or Modis Europe Ltd. Our Candidate Privacy Information Statement which explains how we will use your information is available on the Modis website.

Skills Required