Senior Full-Stack QA Engineer, Poland

About this role

Description Trivago Innovation Center is looking for an experienced, hands-on Senior Full-Stack QA Engineer to join our Polish team and ensure the quality of our B2C e-commerce platform. You will take a comprehensive, end-to-end approach to testing across the frontend, backend, APIs, integrations, and data layers, helping us deliver reliable and seamless customer experiences. This is an individual contributor role that works closely with Product and Engineering and reports to the Product Manager.

About the role Develop, document, and continuously improve QA processes and testing strategies across frontend, backend, API, and data layers. Plan, prioritize, and execute manual functional, regression, integration, and end-to-end tests for web and mobile products. Design and maintain detailed, well-structured test suites and test cases covering complete customer journeys and business-critical flows. Review product requirements, technical specifications, and user stories; provide timely feedback on testability, risks, and acceptance criteria.

Test APIs and system integrations, validate data flows and backend responses, and investigate issues using relevant diagnostic tools. Use SQL to verify data accuracy, consistency, and business logic throughout the testing process. Identify, reproduce, document, report, and track defects; collaborate with developers to investigate root causes and verify fixes. Partner closely with Product and Engineering teams to define testing priorities, assess release readiness, and improve product quality.

Contribute to test automation and the ongoing improvement of QA tools and methodologies, where relevant. Requirements 5+ years of experience in software quality assurance, preferably testing e-commerce platforms, B2C products, or complex web applications. Strong hands-on experience with manual testing, including frontend, backend, integration, regression, and end-to-end testing. Practical experience with API testing and HTTP traffic analysis using tools such as Postman, Fiddler, and browser developer tools.

Solid SQL knowledge and the ability to query and validate data; familiarity with scripting. Proven ability to write clear, accurate, and comprehensive test plans, test suites, and test cases. Experience working in an Agile/Scrum development environment. Strong analytical and troubleshooting skills, with the ability to independently investigate complex, cross-layer issues. Excellent communication and collaboration skills, with a hands-on and proactive approach.