Senior Load Tester

Employer: International cassino games studio Location: until june 2026 remote, then 5 days from the office in 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     Your role is to: -> 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;   Your skills and experiences: -> 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;   If interested, please apply safely through this portal (application rules are in accordance with GDPR). Employment agency Nr 17138.