Performance Tester with Gatling (f/m/x)

Sii is the leading technology consulting, digital transformation, engineering, and business services vendor in Poland. The company employs more than 7,300 professionals and implements projects in various industries for clients worldwide. Sii has won the Great Place to Work title 10 times in a row, demonstrating a friendly work environment.

• Minimum 5 years of professional experience in software testing, including performance testing
• Solid understanding of performance engineering concepts and optimization (architectural patterns, databases, microservices, queues, JVM tuning)
• Solid understanding of performance testing methodologies, strategies, and workload profiles
• Hands-on experience with Gatling (must-have) and programming skills in Java, including a good understanding of OOP principles and best practices (SOLID, DRY, YAGNI, KISS)
• Previous work with cloud platforms such as Azure or AWS
• Practical experience with containerization and orchestration tools, especially Docker
• Familiarity with observability and monitoring tools such as Grafana, Kibana, InfluxDB, Prometheus, Azure Application Insights, and Amazon CloudWatch
• Experience working with CI/CD pipelines (e.g., GitHub Actions, Azure DevOps) and version control systems such as Git
• English proficiency at a minimum B2 level
• Fluent Polish required
• Residing in Poland required

Nice to have:

• Performance testing experience (JMeter, Python, Kubernetes), including mobile apps
• Familiarity with GitHub Copilot

• Developing, maintaining, and deploying performance testing scripts, load generators, and executing performance tests
• Defining performance testing scope, goals, and success criteria
• Gathering and refining performance requirements with stakeholders
• Analyzing performance results on both the client and server sides
• Identifying bottlenecks using observability tools like Azure Application Insights, Amazon CloudWatch, and Grafana
• Preparing clear reports with insights and recommendations
• Supporting and guiding development teams on performance best practices while promoting a shift-left approach to performance testing
• Helping define and improve performance engineering standards

Employment decisions are made solely on qualifications and competencies. Commitment to equal treatment regardless of protected characteristics and promotion of a diverse and inclusive work environment. Residing in Poland is required.