Senior Software Engineer in Test IV (Python) - Fixed Term

Company at a Glance OpenX is focused on unleashing the full economic potential of digital media companies. We do this by making digital advertising markets and technologies that are designed to deliver optimal value to publishers and advertisers on every ad served across all screens. At OpenX, we have built a team that is uniquely experienced in designing and operating high-scale ad marketplaces, and we are constantly on the lookout for thoughtful, creative executors who are as fascinated as we are about finding new ways to apply a blend of market design, technical innovation, operational excellence, and empathetic partner service to the frontiers of digital advertising. At OpenX Poland, we’re looking for talented, communicative, and curious engineers to join our team in Cracow, Poland. Currently, we’re looking for a Software Developer in Test IV. Temporary backfill until August 31, 2027. Our exchange handles billions of ad requests daily, connecting thousands of publishers with demand partners across the global advertising ecosystem. You will be part of a product engineering team focused on business-critical workflows that support how advertising transactions are configured, processed, and validated across OpenX. As an SDET IV, you will take ownership of quality for business logic, backend APIs, data flows, and cross-system integrations. You will design and improve automated test coverage, identify risks early, support CI/CD and release readiness, and help the team ensure that platform behavior remains consistent with business requirements and financial processes. Team setup You will join a cross-functional product engineering team with a dedicated Product Manager, Scrum Master, Engineering Manager, QA engineers, frontend and backend engineers, and support from data analysts and UX designers when needed. This setup gives you direct access to product context and a real opportunity to influence business requirements, solution design, test strategy, and release quality. If you’re: Analytical - able to connect business requirements, system behavior, and product risk. Open-minded - happy to give and receive feedback, not afraid to fail, and move on. Proactive - always looking for practical solutions and ways to move forward. Self-organized and self-motivated. We want to talk to you.