Product Security Engineer

Full-Time 37.5 hours, over 5 days (minimum 4 days per week in the office)
Role Summary

We are looking for a senior, hands-on security engineer to own the security of our AIVR product stack end to end. You will spend your time thinking like an attacker, finding weaknesses in our systems before anyone else does, and then coordinating with the engineering teams to remediate.

You will pull the architecture apart, work out the realistic attack paths, test them, prove what’s exploitable, explain the impact to the engineers who own them, help them work out a sensible fix, and then verify the fix.

This is a technical role in a team that likes getting things done. It is not a compliance or GRC position.

Your job is to make the product secure by continuously scouting for vulnerabilities and red teaming the AIVR product.

• Edge devices on trains. Embedded Linux devices with cameras and other sensors, fitted to in-service rolling stock. They are remote, physically outside our control, and connect back to us over 4G/5G.
• AWS cloud platform. A comprehensive and complex data processing platform, including serverless and containerised services developed predominantly in Python and hosting 7+ PB of data.
• Web applications. The AIVR web applications used across the rail industry, with multi-tenant work spaces, sharing tools and integrations.
• Machine learning infrastructure. Training and inference workloads running in a 3rd party data centre.

• Continuously red team our product stack: threat modelling, penetration testing, code and configuration review, and adversarial thinking applied across devices, cloud, applications and ML infrastructure.
• Highlight findings and their impact. Work with the team that owns the system to explain findings and validate fixes.
• Input into AWS security architecture with the Platform team: IAM, organisation and account structure, networking, encryption, logging and detection.
• Evaluate device-side security with the Device team: secure boot and update signing, credential and certificate lifecycle, remote access, tamper and theft scenarios.
• Harden the software supply chain: dependency and container vulnerability management, SBOMs, CI/CD pipeline integrity, and CVE exposure.
• Build security into the way we ship: static and dynamic analysis, IaC and container scanning, secrets detection, and secure coding guidance that engineers will actually use.
• Improve detection and response: make sure the right things are logged and alerted on and contribute hands‑on when there is an incident. Incident response here is an all‑hands affair; depending on the incident you may lead it or support whoever does.
• Scope, run and challenge third party penetration tests, and triage reports that arrive through our vulnerability disclosure policy.
• Document what you find and what you change in clear technical writing that engineers can act on and that feeds naturally into our ISO 27001 evidence and customer security assurance, without you having to run that process.
• Raise the bar across the team through code review, threat modelling sessions and mentoring, so that security knowledge spreads rather than bottlenecking on you.

We want someone who is comfortable ranging across cloud, embedded, web and infrastructure in a single week. Nobody will have depth in every area below; we would rather have real depth in two or three and the curiosity to pick up the rest.

• Substantial hands‑on security engineering experience (five or more years) in teams that ship software, with a strong offensive mindset.
• Deep, practical AWS security knowledge: IAM and Organizations, S3, VPC networking, Cloud Trail, and infrastructure as code.
• Strong Linux fundamentals, on both servers and embedded devices.
• The ability to…