Senior QA Engineer

About the company: KIEFER is building Greece's integrated AI ecosystem. From renewable energy infrastructure and AI systems to robotics and enterprise applications, we connect the technologies that power Europe's intelligent future. Founded in 2014, KIEFER has delivered 600MW+ of energy projects and is now developing sovereign AI infrastructure, enterprise AI products and physical AI systems for Greece and Southeast Europe. About the role: We are looking for a Senior QA Engineer to join our established QA practice and help us scale quality across Sophea products. You will work as part of a horizontal QA function, collaborating with different product and engineering teams. The role combines hands-on test automation with ownership of QA processes, CI quality gates, test reporting, and defect visibility. You will review existing test suites, identify the most important quality risks, and improve how we test frontend, backend, APIs, and AI-powered features. An important part of the role will be developing practical ways to evaluate AI-generated output, where traditional automated testing may not be enough. Our stack includes 10+ Python and TypeScript services across multiple repositories. We use pytest, Vitest, and Playwright, with GitHub Actions for CI, along with coverage, mutation testing, and flaky-test reporting tools. What you will do: Build and maintain automated tests for frontend, backend, and API services. Develop unit, integration, and end-to-end test coverage. Improve CI quality gates, test reporting, defect visibility, and release reliability. Review existing test suites, identify coverage gaps, and reduce flaky tests. Develop practical methods for validating AI-generated output using mock and real model interactions. Work closely with engineering teams to improve testing practices and support production-ready releases. What you will need: 6+ years of experience in QA or test engineering, including strong hands-on test automation experience. Experience testing applications and services built with Python, TypeScript/JavaScript, or Java, using frameworks such as pytest, Vitest, Playwright, or similar. Strong understanding of unit, integration, API, and end-to-end testing in production environments. Experience with CI/CD pipelines, automated quality gates, test reporting, and reviewing existing test suites. Active use of AI tools and agents in daily QA work, with the ability to apply them effectively and critically review the results. High autonomy, strong communication skills, and the ability to collaborate, share knowledge, and work constructively across different teams. Nice to have: Experience testing AI or LLM-based products and evaluating AI-generated output. Experience with mutation or contract testing tools such as StrykerJS, mutmut, or Pact. Experience with load, performance, or event-driven system testing. What is there for you: High-impact role influencing product stability. Ownership to shape QA practices from the ground up. Exposure to cutting-edge AI products. Career growth as the organization scales. Opportunity to dive into adjacent tech areas, such as DevOps and Security testing.