Principal Software Engineer @ OpenX

2 days ago

Remote Kraków, Czech Republic OpenX Full time
  • 5+ years of experience with building SaaS applications using JavaScript/TypeScript (including Node.js)
  • Experience with database system design, RDBMs, or NoSQL
  • Openness to work with other languages like Python
  • Experience with developing back-end - nice to have
  • Experience with Amazon Web Services or Google Cloud Platform - nice to have
  • Communicative Polish and English

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.


We’re seeking a Principal Engineer with strong platform and cloud expertise to lead large-scale integrations and enhance the scalability and performance of our platform. You’ll join a talented team to design and develop real-time services, working closely with partner engineering and product teams to deliver secure and robust solutions.
An ideal candidate is:

Open-minded – Welcomes feedback, learns from failure, and adapts quickly to change.

Proactive – Takes initiative to identify problems and drive thoughtful, effective solutions.

Self-motivated & Organized – Manages priorities independently and follows through with clarity and accountability.


We are operating at a scale:

  • 100% Cloud-based (GCP) platform
  • Over 370 billion Ad requests every day
  • Over 120 000 CPU daily
  • Over 140 TB RAM daily
  • Over 50 PB of data per week
  • Over 1200 production deployments a month


,[Lead the architecture and technical vision for platform integrations, ensuring high performance, security, and scalability., Design and build systems that enable partners to connect and operate real-time services efficiently and securely., Work with partner engineering and product teams to plan, build, and launch integrations that meet business and technical goals., Deliver critical platform features from design through implementation, testing, rollout, and adoption., Identify and address technical debt, performance bottlenecks, and scalability risks before they impact customers., Champion architectural patterns and platform capabilities that improve developer velocity and operational reliability., Promote engineering excellence through constructive code reviews, mentoring, and driving improvements in code quality, architecture, and platform best practices.] Requirements: Java, Cloud, Kubernetes, REST API, Distributed computing, Google Cloud Platform, Golang, PostgreSQL, Docker, JVM, Spring, AWS Tools: Jira, Confluence, GitHub, GIT, Cloud Build, Agile, Scrum, Kanban. Additionally: Small teams, International projects, Private healthcare, Lunch card, Multikafeteria, Life & group insurance, Flat structure, Free coffee, Canteen, Bike parking, Shower, Free snacks, Free beverages, Free lunch, Free parking, In-house trainings, Modern office, No dress code.

  • Senior Software Engineer

    2 days ago

    Remote, Kraków, Czech Republic OpenX Full time

    5+ years of similar position working experience in Python Experience with database system design, RDBMs (MySQL, Postgres), or NoSQL Experience with JavaScript - nice to have Experience with one of the Cloud - GCP or AWS Experience working in digital media, marketing technology, or advertising technology is a big plus Experience in REST API or GraphQL At...

  • Senior Software Engineer

    2 weeks ago

    Remote, Kraków, Czech Republic OpenX Full time

    5+ years of similar position working experience in PythonExperience with database system design, RDBMs (MySQL, Postgres), or NoSQLExperience with JavaScript - nice to haveExperience with one of the Cloud - GCP or AWSExperience working in digital media, marketing technology, or advertising technology is a big plusExperience in REST API or GraphQL At OpenX, we...

  • Senior Data Scientist

    2 days ago

    Remote, Kraków, Czech Republic OpenX Full time

    5+ years of experience in data science, with a strong technical foundation. 1+ year of experience leading data science teams or technical projects. Demonstrated ability to prioritize effectively, delegate tasks, and manage competing demands. Excellent communication, leadership, presentation, and collaboration skills. Proficient in Python and SQL Hands on...

  • Senior Test Automation Engineer @ OpenX

    2 days ago

    Remote, Kraków, Czech Republic OpenX Full time

    5+ years of test automation experience Proficiency in Java and ability to improve, debug, modify and maintain an automation framework codebase Experience with SQL Experience using CI/CD tools like Jenkins, Spinnaker, or Cloud Build Excellent troubleshooting skills to triage complex issues Experience operating in an agile environment Bachelor’s degree in...

  • Software Principal Engineer

    1 week ago

    Remote, Warszawa, Czech Republic Dell Technologies Full time

    Essential RequirementsBachelor's degree in Computer Science or related field10+ years of proven experience in complicated system, e.g. critical telecom product, OS (multi-threading, locks, scheduling), storage protocols (NFS, CIFS, iSCSI), storage technologies (SAN, NAS, RAID, OSD, snapshot, replication), networking, device drivers, clustering, etc.Strong...

  • Senior Test Automation Engineer

    2 days ago

    Remote, Kraków, Czech Republic OpenX Full time

    5+ years of test automation experience Proficiency in JavaScript and ability to improve, debug, modify, and maintain an automation framework codebase Openness to work with other languages like Python Experience in using test design techniques Experience using CI/CD tools like Jenkins or Spinnaker Excellent troubleshooting skills to triage complex...

  • Software Principal Engineer

    2 days ago

    Remote, Warszawa, Czech Republic Dell Technologies Full time

    Essential Requirements Bachelor’s degree in Computer Science or related field 10+ years of proven experience in complicated system, e.g. critical telecom product, OS (multi-threading, locks, scheduling), storage protocols (NFS, CIFS, iSCSI), storage technologies (SAN, NAS, RAID, OSD, snapshot, replication), networking, device drivers, clustering,...

  • Senior Data Scientist

    2 weeks ago

    Remote, Kraków, Czech Republic OpenX Full time

    5+ years of experience in data science, with a strong technical foundation.1+ year of experience leading data science teams or technical projects.Demonstrated ability to prioritize effectively, delegate tasks, and manage competing demands.Excellent communication, leadership, presentation, and collaboration skills.Proficient in Python and SQLHands on...

  • Remote Principal Engineer

    2 weeks ago

    Remote, Kraków, Czech Republic uSoftware Full time

    Minimum Qualifications:At least 5 years of proven experience in software engineering including roles like Senior/Staff/Principal Engineer, Lead Developer, or Software ArchitectExperience in driving projects which influenced at least 2-3 engineering teamsExcellent problem-solving and communication skillsSolid understanding of software fundamentals (Data...

  • Senior Test Automation Engineer

    3 days ago

    Remote, Kraków, Czech Republic OpenX Full time

    5+ years of test automation experienceProficiency in JavaScript and ability to improve, debug, modify, and maintain an automation framework codebaseOpenness to work with other languages like PythonExperience in using test design techniquesExperience using CI/CD tools like Jenkins or SpinnakerExcellent troubleshooting skills to triage complex issuesExperience...