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Senior Performance Test Engineer (k6)

XM Poland

onsite
Posted Aug 28, 2026

**Role & seniority: ** Senior Performance Test Engineer (k6); likely leads/mentors over time

**Stack/tools: **

  • k6 (JavaScript/TypeScript)

  • REST + GraphQL performance testing

  • Docker, Kubernetes (incl. HPA/resource limits)

  • Spring Boot, JVM performance best practices

  • Grafana, Prometheus (monitoring/analysis)

  • CI/CD: GitLab CI, Jenkins

  • Mentions: distributed tracing tools (Jaeger/OpenTelemetry) as advantage; service mesh (Istio/Linkerd) as advantage

  • Top 3 responsibilities:

    1. Define/refine company performance testing strategy

    2. Build/maintain reusable k6 performance test scripts; run load/stress/soak tests for REST/GraphQL

    3. Monitor/analyze results (Grafana/Prometheus), identify bottlenecks, and collaborate on fixes; integrate into CI/CD pipelines

  • Must-have skills:

    • 5+ years QA, 2+ years hands-on performance testing (k6/Gatling)

    • Strong JavaScript/TypeScript for test scripting

    • API performance testing experience: rate limiting, caching strategies

    • Familiarity with Spring Boot/microservices

    • Experience with Docker/Kubernetes performance-related configuration

    • Grafana/Prometheus proficiency

    • CI/CD integration experience (GitLab CI, Jenkins)

  • Nice-to-haves:

    • gRPC, WebSockets, HTTP/2 performance testing

    • JVM tuning and database performance optimization

    • Cloud-native performance strategies; **service mes

Full Description

The Role

  • We are looking for a Senior Performance Test Engineer (k6) to join our high-performing team and contribute to the performance, scalability, and reliability of our trading platforms. This role involves hands-on performance testing and analysis in a high-throughput, low-latency environment, collaborating closely with development and infrastructure teams to ensure system efficiency and stability.

You will work with modern tools and practices, leveraging K6 with JavaScript/TypeScript, containerized environments (Docker, Kubernetes), and cloud-native performance strategies. While this is a technical role, there may be opportunities to mentor and guide engineers on the team as your role evolves.

The main responsibilities of the position include

  • Define and refine performance testing strategy across the company
  • Develop and maintain performance testing scripts using K6 and JavaScript/TypeScript, focusing on reusable and scalable testing approaches
  • Execute various types of performance tests (load, stress, soak) on REST and GraphQL APIs
  • Monitor and analyze test results using tools like Grafana and Prometheus, providing actionable recommendations
  • Collaborate with engineering teams to identify and troubleshoot system performance bottlenecks
  • Apply performance best practices in Spring Boot, JVM, and microservice-based environments
  • Integrate performance tests into CI/CD pipelines (GitLab, Jenkins) to enable continuous validation
  • May take on mentorship or leadership responsibilities over engineers within the team over time

Main requirements

  • BSc/MSc in Computer Science, or related discipline
  • 5+ years of hands-on experience in QA
  • 2+ years of experience in performance testing using tools like K6 or Gatling
  • Proficiency in JavaScript/TypeScript for writing test scripts
  • Strong experience in API performance testing (REST, GraphQL), including rate limiting and caching strategies
  • Familiarity with Spring Boot applications and microservices architecture
  • Experience working in Docker/Kubernetes environments, including performance-related configurations (HPA, resource limits, etc.)
  • Proficiency with monitoring/observability tools such as Grafana, Prometheus, etc.
  • Experience integrating testing into CI/CD pipelines (GitLab CI, Jenkins)

The following will be considered an advantage

  • Experience with gRPC, WebSockets, and HTTP/2 performance testing
  • JVM tuning and database performance optimization expertise
  • Familiarity with cloud-native performance strategies and service mesh technologies (Istio, Linkerd)
  • Exposure to distributed tracing tools like Jaeger or OpenTelemetry
  • Experience in managing/leading a team

Benefit from

  • Attractive remuneration package
  • Intellectually stimulating work environment
  • Continuous personal development and international training opportunities

The Hiring Experience: What Awaits You Let’s Connect – Intro Chat with Talent Acquisition Deep Dive – First Interview with Your Future Team Final Connection – Final Interview

All applications will be treated with strict confidentiality!

K6JavaScriptTypeScriptPerformance TestingDockerKubernetesGrafanaPrometheusREST APIGraphQLSpring BootCI/CDGitLabJenkinsJVM TuningMicroservices

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