Senior Performance Tester

About the role

In this role, you will validate the responsiveness, scalability, and reliability of applications under various load conditions. You will design, implement, and execute performance test scenarios that simulate realistic user behavior and system stress. You will collaborate closely with developers, DevOps, and testers to ensure performance considerations are embedded throughout the software lifecycle.

Also, you will take ownership of performance testing strategy, architecture, and tooling alignment.

Responsibilities

• Design, develop, and execute performance test plans using tools like k6 and xk6-browser.
• Collaborate with developers and testers to define performance criteria and thresholds.
• Configure and execute performance tests in CI/CD environments (e.g., via GitHub Actions).
• Collect and analyze system metrics using Prometheus and visualize results in Grafana dashboards.
• Capture and analyze browser/network traffic using tools such as MITMProxy and Wireshark.
• Maintain test configuration files and input data.
• Identify performance bottlenecks and provide actionable recommendations.
• Monitor and report system behavior under load and stress conditions.
• (Senior PE) Define performance strategy and standards for services or projects.
• (Senior PE) Guide infrastructure alignment using Kubernetes based containers for scalable test execution.

Requirements

• 7+ years in performance engineering
• Experience with performance testing tools (e.g., k6, xk6-browser for scripting browser/API load tests)
• Experience with MITMProxy, Wireshark for capturing and inspecting traffic
• Experience with observability & monitoring tools (e.g.,Prometheus and Grafana)
• Experience with Docker and Kubernetes for scalable, isolated test environments
• Experience with CI/CD Integration:(e.g., GitHub Actions)
• Designing performance scenarios aligned to business-critical flows
• Understanding of backend performance patterns (latency,throughput, error rate)
• Interpreting logs and metrics to detect performance degradation
• Excellent ability to work independently to deliver, but function and collaborate as part of a team, while at the same time being aware of own limitations and not afraid to seek clarification, advice and approval for decisions when required.
• Very high level of English verbal and written (European Framework Level C1 or higher) or equivalent.
• University Degree in the field of computer technology (not nontechnical) or successful 3 years' post-secondary education in IT technical studies in a computer- related field followed by minimum 4 years' professional experience in IT.
• Certifications: Certified Tester Performance Testing preferred