Performance Test Engineer

Join us in bringing joy to customer experience. Five9 is a leading provider of cloud contact center software, bringing the power of cloud innovation to customers worldwide. Living our values everyday results in our team-first culture and enables us to innovate, grow, and thrive while enjoying the journey together. We celebrate diversity and foster an inclusive environment, empowering our employees to be their authentic selves. About the Role The Performance Test Engineer will be a core member of Five9's Performance Engineering team, responsible for designing, building, and executing performance tests across our cloud contact center platform. The ideal candidate has hands-on experience creating realistic workload models, running load and stress tests, and turning test results into clear, actionable findings for development teams. They will apply modern AI-assisted tooling to accelerate test analysis and anomaly detection, helping Five9 deliver consistently fast and reliable product experience. Key Responsibilities Design, develop, and maintain performance test scripts and scenarios using tools such as k6, Gatling, JMeter, or Python Build and maintain realistic workload models that accurately represent production traffic patterns and user behavior Define and document performance test objectives, entry/exit criteria, and service level objectives (SLOs) Execute a range of test types including baseline, load, stress, soak, spike, and scalability tests Analyze test results to identify bottlenecks, regressions, and areas of concern; produce clear written findings and recommendations Collaborate closely with developers, QA engineers, and architects to share results and support remediation efforts Set up and maintain performance test environments and test data in alignment with production configurations Integrate performance tests into CI/CD pipelines to enable continuous performance validation Define and configure monitoring dashboards and alert thresholds using observabili