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.

About the role

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.

You will be part of the development team focused on exchange features for connected devices (CTV). Our exchange handles billions of ad requests daily connecting thousands of publishers with demand partners. Each request produces data events that have to be processed to extract business value from them.

Temporary backfill until August 31, 2027.

Ideal Candidate

• Open-minded - happy to give & receive feedback, not afraid to fail, and move on
• Proactive - always want to find a satisfying solution
• Self-organized and self-motivated

Project

The Upsiders team develops the auction and revenue mechanics that determine how transactions are priced, processed, and monetized across OpenX. Our work focuses on bid economics across both deals and the open exchange, including pricing, floors, fees, rebates, auction behavior, revenue calculation, and real‑time reconciliation. We build systems that help ensure real‑time platform calculations reflect actual financial processes and commercial agreements, enabling OpenX to support flexible business models, optimize monetization, and deliver accurate revenue outcomes for buyers, publishers, and internal teams.

• Frontend: JS/TS, React, Material UI
• API: Python, Java
• Backend: Java, Go, Erlang, Elixir
• CICD: Cloud build, Spinnaker

What We Offer

• Employment contract (22 595-25 254 PLN gross/monthly) OR B2B (181 zł – 202 zł PLN net/hourly)
• Working with the newest technologies such as Cloud Computing (GCP)
• Challenges at work that are difficult to find anywhere else!
• Solving important problems in a scale
• Joining a company that is growing and scaling
• Flexible working hours & remote work option

Key Responsibilities

• Test large-scale event processing systems and back‑end applications
• Involved in all phases of product development, starting from requirements to validation and deployment
• Analyze and improve efficiency, scalability, and stability of applications
• Work in a focused and nimble team that collaborates on common problems across products and across focus areas
• Own components, processes, and workflows that demand professionalism, excellent communication, teamwork, and documentation skills
• Create, maintain, and improve automation test suites/frameworks
• Monitor and maintain QA CI pipelines, collaborate on CD enablement
• Conduct root cause analysis of issues and provide solutions for better coverage and maintainability
• Effectively communicate and being a crucial member of both the project teams and QA organization
• Be exposed to a broader set of problems, which allows for fast career growth and proximity to abundant technical problems

Required Qualifications

• 5+ years of test automation experience
• Proficiency in Java OR Python and ability to improve, debug, modify and maintain an automation framework codebase
• Experience using CI/CD tools like Jenkins, Spinnaker, or Cloud Build
• Excellent troubleshooting skills to triage complex issues
• Experience operating in an agile environment
• Communicative Polish and English languages
• Bachelor’s degree in Computer Science or equivalent degree

Desired Characteristics

• Experience in using Google Cloud Platform, k8s, and docker
• Experience with UI testing
• Familiarity with advertising technologies and the advertising ecosystem

Benefits (Employment Contract)

• Annual performance bonus
• Tax‑deductible system due to copyright protection: 75%
• Private health care for you and your family (covered by OpenX)
• Private life and travel insurance (Covid insurance included)
• MultiKafeteria program
• Training: access to the LinkedIn learning platform and Tech workshops
• Holiday Allowance
• Pension scheme (PPK from PZU)
• Additional paid day off
• Free parking lot
• Access to peer to peer recognition platform
• Monthly work‑from‑home allowance and one‑time payment when you join us to help you set up your home office
• We celebrate team members' important personal milestones (vouchers, gifts)

Equal Employment Opportunity Statement

OpenX is committed to equal employment opportunities. It is a fundamental principle at OpenX not to discriminate against employees or applicants for employment on any legally‑recognized basis including, but not limited to: age, race, creed, color, religion, national origin, sexual orientation, sex, disability, predisposing genetic characteristics, genetic information, military or veteran status, marital status, gender identity/transgender status, pregnancy, childbirth or related medical condition, and other protected characteristic as established by law.