Big Data Engineer

About the Team We are looking for a skilled and motivated Big Data Engineer to join our dynamic ad-tech engineering group. In this role, you will help to design and expand core components of a large-scale DSP (Demand Side Platform). The position is based in Warsaw, with broad opportunities to collaborate on international projects across diverse geographies, including the US, Korea, India, and the UK. Your expertise will directly contribute to building high-performance, modern services central to delivering targeted advertising solutions to millions of end-users. Daily interactions include working cross-functionally on system design, code implementation, code review, documentation, and ensuring overall solution quality. Operating for several years as part of a high-growth, multi-disciplinary, and multicultural environment, our team manages technology stacks and platforms critical to the continued expansion of our ad technologies portfolio. If you are ready to have direct impact on ad-tech product innovation, join us to shape the next era of data-driven advertising platforms. Key Responsibilities • Partner with data scientists, product managers, and engineering peers to enhance and refine data processing systems • Design and maintain scalable, optimized data pipelines for large-scale data collection, processing, and storage • Collaborate to improve advertising attribution methodologies • Participate in R&D projects focused on cloud-based services • Establish and advocate best coding practices • Translate business requirements into robust technical solutions • Conduct A/B testing and performance analysis of attribution models • Maintain software quality through thorough testing and code reviews • Provide status updates on task progress Technologies Used • Python, Java, Scala • Docker, Kubernetes • Flink, Airflow • Snowflake, Apache Ignite, PostgreSQL, MySQL • AWS: S3, Athena, Glue, EMR (Spark) • GraphQL, REST APIs Core Qualifications • Minimum five years of commercial experience in Python, Java, or Scala • Strong experience with big data technologies (e.g., Hadoop, Spark, MapReduce) • In-depth knowledge of database (SQL/NoSQL) platforms (e.g., Snowflake, PostgreSQL, MySQL, DynamoDB) • Familiarity with Kubernetes and stream processing frameworks (e.g., Flink, Apache Ignite) • Proven ability to optimize SQL queries and manage large datasets • Experience using orchestration tools such as Airflow • Hands-on experience with AWS • Understanding of software design patterns and effective version control (Git) • Excellent English skills for technical communication and documentation • University degree in Computer Science, Telecommunications, or similar Preferred Qualifications • GoLang experience • Previous experience with GraphQL • AWS service administration skills • Microservices or serverless solutions development • Advanced knowledge of container technologies (Docker, Kubernetes) What We Offer • Team Environment: • Supportive, friendly atmosphere within a multi-disciplinary, multicultural team • Wide range of technical and soft-skill trainings, access to e-learning platforms • Experience working with the latest market technologies • Monthly integration budget and regular team-building activities • Participation in local and international conferences • Options to contribute to research (scientific papers, projects, patents, side-projects) • Equipment: • High-spec laptop and PC workstation with dual external monitors (Windows and Linux available) • Benefits: • Private medical coverage (extendable to family members) • Multisport card, life insurance, lunch card • Partially subsidized English courses • Free language learning options (including Korean) • Discount programs for entertainment, products, and services • Free access to select science and cultural centers • Opportunity to test new and emerging technology devices • Location: • Centrally located office in Warsaw Spire, near the metro • Attractive relocation package • Flexible hybrid work model (3 in-office days per week)