QA engineer
Marcina Kasprzaka 4, Warszawa
Opensignal
About the role
We are looking for a Mid QA Engineer to join our team and help us ensure the quality of our web-based data visualization application.
Your main focus will be on the web application, working closely with developers, product owners, and other team members to deliver high-quality releases. While your current tasks will primarily include testing new features and verifying release candidates, we want you to also take an active role earlier in the development cycle – during planning and requirement analysis – to bring in your quality perspective.
What will you be doing
Plan, design, execute, and maintain manual and automated tests (E2E, integration, API, performance, and security).
Actively participate in Scrum ceremonies (planning, refinement, daily, review, retrospective).
Verify release candidates and contribute to release quality decisions.
Create, maintain, and improve test documentation.
Work with GitLab CI/CD pipelines for automated test execution.
Collaborate with developers on test strategies, unit/integration testing, and debugging issues.
Perform performance checks (Lighthouse) and basic security testing (OWASP Top 10).
Report and track issues using Jira.
Optionally, support junior QA engineers in the future.
Must-have requirements
3+ years of commercial experience as a QA Engineer.
Strong programming/testing skills in TypeScript (JavaScript alone is not sufficient).
Advanced API testing (REST/GraphQL) with Postman and Cypress/Jest automation.
Experience with Cypress for E2E testing (intermediate to advanced).
Familiarity with Jest for unit and integration testing.
Basic SQL (PostgreSQL).
Basic Docker (running containers, accessing logs).
Git (intermediate – branching, merge requests, conflict resolution).
Performance testing (intermediate – Lighthouse).
Debugging and log analysis (basic).
Task and bug management tools (Jira).
Release quality monitoring (smoke/regression testing, release candidate verification).
Excellent English communication skills (B2+).
Soft skills: proactivity, attention to detail, strong communication, independence, collaboration mindset.
Nice-to-have requirements
Experience with testing AI-powered functionality (e.g. conversational interfaces, data analysis features)
Experience with Playwright
SQL (intermediate – complex queries, JOIN, aggregations).
Security testing (basic – OWASP Top 10).
Participation in code reviews (intermediate – quality/testability feedback).
Integration of tests with CI/CD pipelines.
Experience with supporting junior QA engineers.
Contribution to requirement analysis and refinement.
Basic Python knowledge (e.g. writing simple scripts, test automation, data handling).
What we offer
A chance to work on cutting-edge products (data visualization & GPU-accelerated databases).
Collaborative environment with a strong engineering culture.
Opportunity to grow your skills in automation, performance, and quality processes.
Flexible, remote-first work setup (with occasional office presence – min. 1 day/month).
Comprehensive private family health care package with dental care
Multisport Plus Card
About Us
Opensignal is the leading global provider of independent insight and data into network experience and market performance. Our user-centric approach allows communication providers to constantly improve their network and maximize commercial performance. Leading analysts, investors, and financial institutions place a high value on our independent analysis, and we are regular contributors to their reports.
Real network experience is our focus, and ultimately, that’s what influences customer choice. Our mission is to advance connectivity for all, and here at Opensignal, the team is leading the industry in enabling operators to link their network experience and market performance in a way that has never before been possible.
With offices in Warsaw, London, Boston, and Victoria, British Columbia, we are truly global, with employees working across four continents and representing over 25 nationalities. We are an equal opportunity employer dedicated to building an inclusive and diverse workforce.
QA engineer
QA engineer
Marcina Kasprzaka 4, Warszawa
Opensignal