Senior Load Tester

O projekcie: Employer: International cassino games studio Location: until first quarter of 2027 remote, then hybrid from Warsaw Salary: up to 5900 EUR net  Cooperation model: B2B Start date: ASAP Recruitment process: 2 online interviews and recruitment task  Technology stack: k6 or Gatling or JMeter or or Locus, Grafana or Datadog or New Relic, WebSocket Wymagania: - 5+ years of hands-on performance and load testing experience on production-scale systems; - Strong practical experience with k6, Gatling, JMeter, or Locust — you've built complex scripts from scratch;  - Good understanding of backend architecture, databases, and how infrastructure behaves under load; - Comfortable reading and interpreting metrics from tools like Grafana, Datadog, New Relic, or similar; - Solid understanding of HTTP, WebSockets, and real-time communication protocols; - Experience testing APIs under load including auth flows, concurrent sessions, and stateful scenarios; - Familiar with CI/CD pipelines and integrating performance tests into automated build processes; - Fluent with Git and working within agile engineering teams; - Curious by nature — you enjoy understanding why a system behaves the way it does under pressure; - Sharp analytical mind — you can look at a wall of metrics and know exactly where to focus; - Clear communicator — you can explain a complex performance issue to a developer and a product manager in the same conversation; - Self-driven — you don't wait to be told there's a problem; you go looking for one; - Fluent English - at least B2+ level; Codzienne zadania: - Design and execute load, stress, spike, and soak tests against critical platform flows;  - Analyze results and pinpoint exactly where and why performance degrades — not just that it does;  - Work closely with backend engineers to understand system architecture and target the right bottlenecks; - Build and maintain performance test scripts that are reusable, version controlled, and easy to update as the product changes;  - Integrate performance tests into CI/CD pipelines to catch regressions early; - Define performance benchmarks and thresholds in collaboration with engineering and product teams; - Monitor platform behavior under load using observability tools and correlate metrics with test results; - Document findings clearly and present actionable recommendations to engineering teams;