Senior Software Security Engineer - Core Platform Services

London

PhysicsX is a deep-tech company with roots in numerical physics and Formula One, dedicated to accelerating hardware innovation at the speed of software.

We are building an AI-driven simulation software stack for engineering and manufacturing across advanced industries. By enabling high-fidelity, multi-physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations - empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive.

The Role

We are recruiting for a Senior Software Security Engineer within our Core Platform Services Team. You will be responsible primarily for writing secure code components that all teams will use across the business. There is a strong emphasis on authentication for this role.

What you will do

• Design and implement platform security features and guardrails.
• Act as an SME for security for the Core Services development team. This includes mentoring, performing threat modeling, and security code reviews.
• Help shape incident response procedures and vulnerability management workflows.
• Support the response team by validating and remediating product security vulnerabilities.
• Contribute to secure coding standards and provide training/mentorship to developers.

What you bring to the table

• 8+ years in a developer role with a strong focus on designing and building security features
• Extensive RBAC/ABAC knowledge and implementation experience
• Experience with user, agent, and machine authentication workflows
• Hands-on experience with secure coding, OWASP Top 10, and threat modeling
• Strong developer skills and extensive experience shipping code to production
• Experienced in CI/CD, IaC, Python and Go
• Track record of balancing pragmatism and security rigor in a fast-paced team
• Thorough knowledge of authentication and authorization protocols (e.g., OAuth, OpenID Connect, SAML, LDAP, etc.)
• Strong communication skills, comfortable working across development teams and managing multiple initiatives

Nice to Have Skills

• Strong understanding of AI security fundamentals
• Participation in bug bounty programs
• Familiarity with the BSIMM framework
• Experience in cloud security including identity and access management and cloud-native services

We value diversity and are committed to equal employment opportunity regardless of sex, race, religion, ethnicity, nationality, disability, age, sexual orientation or gender identity. We strongly encourage individuals from groups traditionally underrepresented in tech to apply. To help make a change, we sponsor bright women from disadvantaged backgrounds through their university degrees in science and mathematics.

We collect diversity and inclusion data solely for the purpose of monitoring the effectiveness of our equal opportunities policies and ensuring compliance with UK employment and equality legislation. This information is confidential, used only in aggregate form, and will not influence the outcome of your application.

We do not include application form fields or job posting noise in this description. The following sections were used for recruitment only and have been omitted to keep the posting focused on the role.

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