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Senior Software Engineer III (Python)

OpenX
Kraków, Polandfull_timeVerifiedPosted 3 Sept 2025
💰 PLN 19,000/yr(PLN 17,000/yrPLN 19,000/yr)

About the role

Company at a GlanceOpenX 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 amazing team in Cracow, Poland. Currently, we’re looking for a Software Engineer (Python).
If you’re:Open-minded - happy to give & receive feedback, not afraid to fail, and move onProactive - always want to find a satisfying solutionSelf-organized and self-motivatedWe want to talk to you.
We are operating at a scale:100% Cloud-based (GCP) platformOver 370 billion Ad requests every dayOver 120 000 CPU dailyOver 140 TB RAM dailyOver 50 PB of data per weekOver 1200 production deployments a month

What we offer:

  • Employment contract (17 000 - 19 000 PLN gross/monthly) OR B2B (139 - 155 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:

  • Design high-performance, distributed, low-latency systems
  • Architect, create and deliver new features and functionality
  • Work with Product to drive the requirements, and own the project end-to-end
  • Work with Engineering and Product teams distributed across multiple locations
  • Analyze and improve efficiency, scalability, and stability of servers and processes
  • Think long-term and be unsatisfied with band-aids
  • Identify unnecessary complexity and remove it, analyse existing solutions

Required Qualifications:

  • 4+ years for similar position working experience in Python along with a Bachelor’s degree in Computer Science or equivalent degree
  • Experience with Java - nice to have
  • Experience with databases system design, RDBMs (MySQL, Postgres) or NoSQL
  • Excellent written and spoken English and Polish skills
  • Experience with Amazon Web Services or Google Cloud Platform - nice to have
  • Experience working in digital media, marketing technology or advertising technology is a big plus
OpenX VALUESOur five company values form a solid bedrock serving to define us as a group and guide the company. Our values remind us that how we do things often matters as much as what we do.
WE ARE ONEWe are one team. There are no exceptions. We are a group of strong and diverse individuals unified by a shared mission. We embrace challenges and win together as a team. We respect and care about our colleagues and cultivate an inclusive culture
WE ARE CUSTOMER CENTRICWe innovate on behalf of our customers. We understand, respect, and listen carefully to our customers. We build great products to solve our customers’ problems. We manage our customers’ expectations clearly and honestly. We are a trusted partner to all of our customers - we act with integrity at all times. We care.
OPENX IS OURSWe are all owners of OpenXWe all have a voice to improve OpenXWe stake our personal and professional reputations on the excellence of our workWe are not interested in just "doing our jobs"; we take ownership to drive results
WE ARE AN OPEN BOOKWe understand and respect what each of us does. We are eager to teach and share what we know with others, both internally and externally. We are eager to learn from others and we ask questions internally and externally. 
WE EVOLVE FASTWe take responsible risks and own and learn from our mistakes. We recognize and repeat success. We actively seek out and provide constructive feedback. We adapt quickly and embrace change. We tackle growth and learning with real urgency. We are endlessly curious.
OpenX TRAITSOur three traits capture what makes a great team member at OpenX.
HUMBLEIdeal team players are humble and demonstrate integrity. They put the team's success above their own, share credit generously, and value collective achievements. They are self-assured, open to coaching, and committed to continuous learning.
DRIVENIdeal team players are results-driven and motivated. They are cu

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OpenX

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