
Senior Performance Test Engineer (k6)
XM • Poland
**Role & seniority: ** Senior Performance Test Engineer (k6); likely leads/mentors over time
**Stack/tools: **
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k6 (JavaScript/TypeScript)
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REST + GraphQL performance testing
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Docker, Kubernetes (incl. HPA/resource limits)
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Spring Boot, JVM performance best practices
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Grafana, Prometheus (monitoring/analysis)
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CI/CD: GitLab CI, Jenkins
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Mentions: distributed tracing tools (Jaeger/OpenTelemetry) as advantage; service mesh (Istio/Linkerd) as advantage
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Top 3 responsibilities:
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Define/refine company performance testing strategy
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Build/maintain reusable k6 performance test scripts; run load/stress/soak tests for REST/GraphQL
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Monitor/analyze results (Grafana/Prometheus), identify bottlenecks, and collaborate on fixes; integrate into CI/CD pipelines
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Must-have skills:
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5+ years QA, 2+ years hands-on performance testing (k6/Gatling)
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Strong JavaScript/TypeScript for test scripting
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API performance testing experience: rate limiting, caching strategies
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Familiarity with Spring Boot/microservices
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Experience with Docker/Kubernetes performance-related configuration
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Grafana/Prometheus proficiency
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CI/CD integration experience (GitLab CI, Jenkins)
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Nice-to-haves:
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gRPC, WebSockets, HTTP/2 performance testing
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JVM tuning and database performance optimization
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Cloud-native performance strategies; **service mes
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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!