Product Security Specialist

This is a technical individual contributor role working 3 days per week remote and 2 days in a London office. We focus on enabling speed without sacrificing safety. That means creating secure-by-default engineering practices, building automation and detections that reduce manual work, researching emerging AI security risks.

About The Role

Our goal is simple: enable engineering teams to move fast and ship securely. We do this by creating the tools, standards, and systems that make secure development seamless. Whether it’s hardening pipelines, tuning detection tooling, or staying ahead of emerging AI risks, we build the connective tissue that keeps Harmonic’s products secure and trusted.

This team operates at the heart of our engineering culture - hands-on, collaborative, and pragmatic. We bridge the gap between security and development, helping both move faster and with more confidence.

You’ll work closely with Engineering and DevOps to integrate security into design, build, and deployment. From managing code scanning and vulnerability tooling to supporting product pen tests and monitoring AI-related risks, you’ll help teams ship fast and safely while building lasting confidence in our products.

What You’ll Do

• Act as the security partner to engineering - helping teams design, build, and ship securely without slowing down development.
• Drive and maintain the tooling that underpins product security - from code scanning and vulnerability detection to CI/CD hardening and reporting.
• Keep a close eye on our own AI systems and tools - monitoring emerging threats and ensuring our AI security posture evolves with the field.
• Lead threat modelling across the product - running structured STRIDE and LINDDUN assessments on new features and system designs, building repeatable templates, and using AI tooling to make it faster and more scalable. The goal is making threat modelling a normal part of how we build, not a separate event.
• Use AI to build and scale the product security function - integrating tools like Claude Code into security workflows, from automated threat modelling to building internal security tooling. A high-performing programme, not necessarily a large one.

What you Bring

• Demonstrable software engineering experience in programming, application design and SLDC.
• Proven experience as a Product or Application Security Engineer in a modern engineering environment - you understand how products are built and shipped.
• Curiosity for emerging threats, especially around AI and ML systems, and a drive to keep our defences one step ahead.
• Excellent communicator who can translate between engineering, security, and go-to-market teams - clear, direct, and grounded in technical reality.
• Hands-on experience with structured threat modelling, including both security and privacy threat modelling methodologies (e.g. STRIDE, LINDDUN).
• Strong Claude Code or equivalent AI coding agent experience. Demonstrated use of agentic AI to build, automate, and accelerate security engineering work. This is a must-have.

What Success Looks Like (6-12 months)

• You'll have fine-tuned our default code security rules and enhanced how engineering teams engage with security scans. A measurable outcome is a significant reduction in raw security findings and a streamlined reporting process that meets engineers where they work.
• You'll have established a consistent and proportional approach to security in design reviews inc threat modelling, making these practices a routine part of engineering.
• You will have introduced automation into our product security workflows, reducing manual effort and allowing the team to focus on more strategic initiatives.
• Most importantly, you'll have introduced a top-tier AI development security programme to ensure our AI systems are safe, secure, and regularly reviewed as the tech landscape evolves.