Hybrid Systems SDET

at Harmonic Security

• Job title: Systems SDET
• Job type: Full Time
• Experience level: Mid level, Senior
• Salary: Not specified
• Degree requirement: No Education Requirement
• Tech skills: AWS, Grafana, Java, Jest, Linux, MacOS, Rust, Selenium, TypeScript
• Location requirements: Hybrid, London, United Kingdom

About the role

• SDET responsible for maintaining automated testing infrastructure across AI security products. Collaborate with engineers to ensure high quality and effective testing across platforms.

Responsibilities

• Design, implement, and maintain test frameworks for our UI, browser extensions, endpoint agent, or backend services - you'll need to apply yourself wherever QA is needed
• Build and run cross-platform tests on Windows, macOS, and Linux - set up test environments to validate our endpoint agent doesn't break user systems
• Expand, run, and investigate load tests to validate system behaviour at scale and ensure we can handle growth
• Investigate bugs, write failing tests, get them fixed - write tests that expose the issue, fix it yourself if you can, or partner with engineers to verify the fix
• Integrate tests into CI/CD - add tests to GitLab CI pipelines, set up quality gates and detailed test reports, keep tests fast and reliable
• Monitor, triage, and improve - file detailed bugs in Jira, escalate critical issues quickly, track test coverage, shape the QA roadmap

Requirements

• 5+ years as an SDET building and maintaining automated test infrastructure
• Strong programming skills in at least one of TypeScript, Java, or Rust
• Experience with modern test frameworks and willingness to learn new ones - at Harmonic we use Jest, Playwright, Bun test, Vitest, JUnit5, Selenium, and Rust's native testing framework (cargo test)
• Cross-platform testing experience on Windows, macOS, and Linux - comfortable setting up test environments, debugging platform-specific issues, and working with VMs or real machines
• CI/CD pipeline knowledge - you know how to integrate tests into GitLab CI (or similar), set up quality gates, and make test reports useful
• Solid debugging skills - comfortable investigating bugs, reproducing issues, and working with engineers to get them fixed
• Proficiency with standard tooling - Git, code review, and CI/CD systems
• **Desirable:**
• Experience with Jira, Notion, GitLab, OpenSearch, Swagger, Grafana, AWS, Figma, or Sentry (or similar tools)
• Comfortable using AI tools to speed up workflows and boost productivity

Benefits

• Competitive pay and meaningful equity with a direct stake in Harmonic’s success
• Comprehensive benefits, pension plan, generous PTO, and flexible hybrid work
• A small, passionate team that values transparency, creativity, and learning
• Thoughtful leadership that cares deeply about growth, impact, and people
• Annual global offsites (past trips include Lisbon and Nashville)
• The chance to directly shape both our product and our culture as we build a category-defining company