Senior Performance Test Engineer - k6 & JavaScript

Our client is an established technology organisation operating across global markets, focused on delivering high-quality software solutions at scale. They prioritise engineering excellence, continuous improvement and collaborative working practices. The company supports distributed teams and invests in modern tooling and infrastructure to enable their engineers to deliver impactful results. With a commitment to quality engineering and developer enablement, they create an environment where experienced professionals can influence technical direction and drive meaningful change.

• 10+ years of experience in performance testing and quality engineering
• Strong proficiency in JavaScript (ES6+) with experience developing automated tests and frameworks
• Hands-on expertise with k6 performance testing tool
• Experience testing REST APIs, GraphQL APIs, and web applications
• Knowledge of performance engineering methodologies and tuning techniques
• Experience with CI/CD pipelines (GitHub Actions, GitLab CI, Azure DevOps, or Jenkins)
• Proficiency using Git and collaborative development workflows
• Experience with Docker and Kubernetes
• Familiarity with cloud platforms (AWS, Azure, or GCP)
• Experience using observability tools such as Grafana, Prometheus, or Application Insights
• Excellent problem-solving and analytical skills
• Strong communication and stakeholder management abilities
• Ability to influence technical direction without direct authority
• Passion for quality engineering and developer enablement
• Continuous learning mindset
• Ability to work effectively across global, distributed teams

• Lead performance testing initiatives using k6 and modern JavaScript frameworks
• Work with cloud infrastructure including Docker, Kubernetes, and AWS/Azure/GCP
• Influence technical direction across global, distributed engineering teams
• Shape quality engineering practices and developer enablement strategies
• Collaborate with stakeholders to drive performance optimisation across REST APIs, GraphQL, and web applications
• Design and develop automated performance testing frameworks using k6 and JavaScript (ES6+)
• Test REST APIs, GraphQL APIs, and web applications for performance, scalability, and reliability
• Implement performance testing within CI/CD pipelines using GitHub Actions, GitLab CI, Azure DevOps, or Jenkins
• Analyse performance metrics using observability tools such as Grafana, Prometheus, and Application Insights
• Collaborate with engineering teams to identify performance bottlenecks and recommend optimisation strategies
• Establish performance engineering methodologies and tuning practices
• Manage code repositories and collaborative workflows using Git
• Communicate findings and recommendations to technical and non-technical stakeholders
• Support global, distributed teams across different time zones