Software Engineer III ( JS/TS) - OpenX

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

You will join the Core Exchange development team at OpenX. Our exchange handles billions of ad requests every day, connecting thousands of publishers with demand partners across the global advertising ecosystem. The platform runs in the cloud across multiple regions and operates at a scale where performance, reliability, correctness, and every millisecond matter.

The role focuses on building tools and workflows that help users manage advertising transactions. These tools help users configure business rules, review transaction setup, and keep platform behavior aligned with business agreements and financial processes.

This is a frontend-first engineering role with meaningful API ownership. Most of your work will focus on building high-quality user interfaces in TypeScript, primarily with React, while also contributing to Python-based APIs that support the product experience end-to-end. In practice, we expect the work to be roughly two-thirds frontend development and one-third API/backend development.

Prior AdTech experience is helpful, but not required.

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 regular collaboration with UX designers. This setup gives engineers direct access to product context and a real opportunity to influence both technical and user-facing decisions.

Design and build high-quality, maintainable user interfaces using JavaScript/TypeScript and React.

Develop and maintain Python-based backend APIs that support frontend workflows and product capabilities.

Translate business rules, pricing logic, and data dependencies into intuitive user experiences and reliable API integrations.

Own features end-to-end, from requirements and technical design through implementation, testing, rollout, and operational quality.

Write and maintain automated tests as part of the development process, including frontend and API-level tests where appropriate.

Collaborate closely with Product, UX, QA, and Engineering to deliver reliable product experiences for enterprise users.

Improve the usability, reliability, and maintainability of existing systems.

Contribute to technical direction, code quality, and engineering practices within the team.

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

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)