Performance Test Engineer
Five9
| Company | Five9 |
| Category | Engineering |
| Location | Porto |
| Remote | Hybrid |
| Employment | Not stated |
| Level | Not stated |
| Salary | Not stated by the employer |
| Posted | 16 Jul 2026 |
| Last verified | 30 Jul 2026 |
| Source | Employer career page (greenhouse) |
Description
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 observability platforms (e.g. Datadog, Grafana, Prometheus)
Triage performance-related defects and contribute to root cause analysis investigations
Maintain performance test documentation, test plans, and results archives
Leverage AI-assisted tooling for automated anomaly detection, intelligent baselining, and accelerated result analysis
Use AI/ML-powered AIOps platforms to identify trends, predict regressions, and reduce mean time to detection (MTTD) for performance issues
Requirements
4–7 years of hands-on experience in performance testing or performance engineering
Practical experience writing and maintaining test scripts in one or more of: k6, Gatling, JMeter, or equivalent
Solid understanding of performance test types and when to apply them (load, stress, soak, spike, scalability)
Experience defining workload models and translating production metrics into test scenarios
Proficiency with application performance monitoring tools (e.g. Datadog, New Relic, Grafana, Prometheus, AppDynamics)
Ability to interpret test results and thread/heap dumps, identify bottlenecks, and communicate findings clearly to technical and non-technical stakeholders
Experience integrating performance tests into CI/CD pipelines (e.g. Jenkins, GitLab CI, GitHub Actions)
Scripting or programming skills in at least one language (Python, JavaScript/Node.js, Java, or Groovy)
Familiarity with AI/ML concepts applied to testing: anomaly detection, intelligent baselining, AIOps, or LLM-assisted diagnostics
Experience testing web applications and APIs (REST, gRPC, WebSocket) under realistic concurrency
Strong written and verbal communication skills; ability to present findings and drive discussions with engineering teams
Nice to Have
Experience testing VoIP, real-time communications, or contact center platforms
Familiarity with containerized test execution environments (Docker, Kubern
You found the opening. Now track it.Tracker, radar and AI drafts in one place.erioun.com →