Job Description

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.

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

Validate backend business logic in large-scale event processing systems running in the cloud, ensuring it behaves consistently with business requirements and financial processes.

Test backend APIs, data flows, and cross-system integrations that support business-critical workflows.

Build domain understanding and analyze requirements, business rules, and technical designs to identify meaningful test scenarios, edge cases, and risks.

Read, analyze, debug, and reason about application and test code to investigate issues and understand system behavior.

Create, maintain, and improve automated test suites and test frameworks.

Monitor and maintain QA CI pipelines and support continuous delivery.

Conduct root cause analysis of issues and provide solutions for better coverage and maintainability.

Collaborate closely with engineers, Product, QA, and other stakeholders throughout the full development lifecycle.

Required Qualifications

5+ years of experience in test automation and software testing.

Strong Python skills for test automation, debugging, and framework maintenance.

Experience testing backend APIs and business logic.

Experience creating, maintaining, and improving automated test suites or test frameworks.

Experience with CI/CD tools such as Jenkins, Spinnaker, or Cloud Build.

Ability to read, analyze, debug, and reason about application or test code.

Excellent troubleshooting skills to triage complex issues.

Strong communication skills, including the ability to raise risks, ask clarifying questions, challenge assumptions, and explain findings clearly.

Experience working in an agile, cross-functional engineering environment.

Ability to communicate effectively in Polish and English.

Desired Characteristics

Familiarity with Java or experience working with Java-based systems.

Experience with Google Cloud Platform, Kubernetes, and Docker.

Experience with advertising technology, marketplace platforms, financial workflows, or revenue-related systems.

Our benefits (on 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)

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

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