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.