Senior Software Engineer - Fully Remote- Technology in London

AI is being run everywhere, by humans and agents. Harmonic Security governs all of it. The AI Governance and Control (AIGC) platform understands user/agent intent and data context in real time, giving security teams visibility and control across every tool and workflow so companies can move faster with AI while minimizing risk. We operate in one of the fastest-moving spaces in tech: the emerging intersection of AI and cybersecurity. It's a market still being defined, and we're among the first to build natively for it - protecting sensitive data in real time, at the endpoint, with minimal friction for the teams using it.

As AI adoption inside the enterprise accelerates, the ability to safely observe, control, and enforce policy in real time isn't a nice-to-have.

How We Work: AI-First by Design. Harmonic exists to help enterprises adopt AI safely and at scale. Everyone here actively leverages AI tools to perform their best work — from deep research and writing to building robust processes and automating complex workflows. We expect every new hire to bring a genuine curiosity for AI and a commitment to using it to work smarter, faster, and with greater creativity.

We're looking for a Senior Product Security Engineer to become the authority on our platform's security architecture - and to write the code that embodies it. You'll inherit a platform where the fundamentals of authentication and authorization, secrets and key management, encryption, and multi-tenant data isolation are already in decent shape, and your job is to sharpen, harden, and evolve them with the depth a dedicated specialist brings that a generalist team can't.

Once you set a standard, the rest of engineering builds to it - that's a formal mandate, not a suggestion. You'll spend the majority of your time writing production code, not producing reports on someone else's.

This is deliberately not a role for someone who wants to sit on a security team finding holes in what other people have already shipped. Take formal ownership of Harmonic's platform security architecture - authentication and authorization, secrets and key management, encryption at rest and in transit, and multi-tenant data isolation - and evolve it beyond what a generalist engineering team has had the focus to do.

Responsibilities:

• Set security engineering standards for the wider engineering team, and have the mandate to enforce them - this isn't advisory.
• Manage your own backlog of platform security improvements, prioritized independently of the product roadmap.
• Run threat modeling and architecture reviews on major new systems and integrations before they ship, so security is designed in rather than retrofitted.
• Keep our own security posture ahead of what our most demanding enterprise customers and their security teams expect from us.
• Stay current on the threat landscape relevant to AI agent security, sensitive data handling, and multi-tenant SaaS platforms.

Qualifications:

• 6+ years of hands-on software engineering experience, with deep specialization in security architecture rather than general backend development.
• Proven track record designing and personally implementing platform-level security controls in production - OAuth/OIDC/SAML, encryption, secrets and key management, multi-tenant isolation.
• Experience with cloud security fundamentals (AWS, GCP, or Azure) - IAM, network security, container and Kubernetes security.
• A track record of shipping secure, reliable, production-grade code, not just reviewing or auditing someone else's.
• Have built or hardened platform-level security in a SaaS company that faces serious enterprise scrutiny (SOC 2, ISO 27001, customer security questionnaires, or similar).
• Are comfortable being the first specialist in this seat, inheriting a solid foundation and having the autonomy - and responsibility - to take it further.
• See the irony and the opportunity in a security company needing excellent security architecture of its own, and want to be the person who delivers it.
• Leverage AI tools as an engineer to help you build smarter, faster and better.

This isn't just a job - it's a chance to help define a category. We're building at the intersection of AI and security, carving out an emerging market where the rules haven't been written yet, and the people who join now will write them.

We believe today's talent is tomorrow's success, and we're committed to creating an environment where you can do the best work of your life.

Benefits:

• Rare market opportunity - Join early in a category-defining company at the convergence of AI and security, where your work directly shapes how enterprises tackle one of the biggest unsolved problems in tech.
• Competitive pay and meaningful equity - A real stake in Harmonic's success, not a token gesture.
• Comprehensive benefits - 401K, pension plan, generous PTO, and flexible hybrid work.
• We collaborate openly, share feedback honestly, and help everyone produce their best work.