SDET at Harmonic Security Inc.
- Location
- London, United Kingdom
- Compensation
- Not Disclosed
Harmonic Security Inc. is building the future of AI governance, and they're looking for a skilled SDET to join their London-based team. You will own the automated testing infrastructure across browser extensions, endpoint agents, and backend services, working with a modern stack including Rust and Playwright.
If you have 5+ years of experience and a passion for building robust, cross-platform quality gates, this is your opportunity to define security for the AI era.
What's the next step?
Harmonic Security Inc. are hiring from Jack's network. Talk to Jack for free and get a direct introduction to the team, if a good fit.
Role overview
Join Harmonic Security Inc. as an SDET to build and own automated testing infrastructure across our entire product surface. You will design frameworks for browser extensions, endpoint agents, and backend services, ensuring high-quality releases across Windows, macOS, and Linux. This is a hands-on technical role essential for securing enterprise AI adoption at scale.
About Harmonic Security Inc.
Harmonic Security provides an AI Governance and Control (AIGC) platform that enables enterprises to adopt AI tools safely without risking data security and privacy. The company offers a ‘zero-touch’ data protection platform utilizing pre-trained, specialized large language models to detect sensitive data with high accuracy. Key offerings include Harmonic Protect, a data protection platform for secure AI adoption, and MCP Gateway, a developer-friendly gateway providing visibility and control over agentic AI ecosystems. The platform addresses ‘Shadow AI’ by offering continuous monitoring of unapproved AI tools, assessing associated risks, and allowing security teams to manage access and block sensitive content from being uploaded. Harmonic employs an end-user ‘nudging’ approach to guide safe AI usage alongside traditional security enforcement.
What you will do
- Design, implement, and maintain robust automated test frameworks for UI, browser extensions, endpoint agents, and backend services.
- Build and manage cross-platform test environments on Windows, macOS, and Linux, including load testing to validate system scalability for global growth.
- Integrate comprehensive quality gates into GitLab CI pipelines, providing clear reporting and fast, reliable feedback to help engineers move with confidence.
Who this is a fit for
- Brings 5+ years of experience as an SDET building automated infrastructure with strong programming skills in TypeScript, Java, or Rust.
- Possesses deep experience in cross-platform testing across macOS, Windows, and Linux, including the ability to debug platform-specific issues using VMs.
- Demonstrates mastery of modern test frameworks and CI/CD systems, using AI tools daily to enhance productivity and ensure production-grade code rigour.
Why this role is remarkable
- Join a category-defining AI security startup already past $10M ARR with strong $26M Series A backing from top-tier investors.
- Shape the foundational testing infrastructure of a rapidly growing company where your technical fingerprints will be on the core product architecture.
- Work in a high-velocity, AI-fluent engineering team that ships fast across a complex, multi-platform stack including Rust, TypeScript, and Playwright.
How Jack & Jill work together
What happens next?
Jack’s an AI agent for job searching and career coaching. He works for you.
Jill is the AI recruiter working for the company. She recruits from Jack’s network.
If your profile’s a match and Harmonic Security Inc. wants to meet, Jill will make the intro. In the meantime, Jack will send you excellent alternatives.