Senior Data Engineer

co.brick talents — powered by AI, powered by people. Senior Data Engineer Location: Hybrid – Warsaw or Kraków (3 days/week from the office – mandatory) Contract: B2B Rate: Up to 200 PLN/h net + VAT Project Duration: Until 30th September 2026 (initial 3-month contract, with a possibility of extension) Start Date: ASAP (no later than the beginning of August) Working Time: Full-time (part-time can be discussed) Onboarding: 2-week onboarding in Malmö, Sweden (fully covered by the client) About the Role We are looking for a Senior AI / Data Engineer / Data Scientist to join an international team building AI-powered solutions for large-scale web content processing, attribute extraction, and market expansion. This is a hands-on role combining data engineering, machine learning, NLP, and applied AI , where you'll design scalable data pipelines, fine-tune ML models, and contribute to the development of AI research agents operating across multiple countries and languages. We're looking for someone with at least 5 years of commercial experience , although our ideal candidate has 7+ years working with data engineering, machine learning, or AI solutions in production environments. Your Responsibilities Design, build, and optimize Spark pipelines for large-scale web content ingestion and processing. Develop data processing and analysis workflows using Python (Polars and/or Pandas). Fine-tune lightweight machine learning models for attribute extraction. Prepare training datasets and ensure high data quality. Evaluate model performance and improve ML pipelines end-to-end. Apply NLP techniques to extract, classify, and reason over information from web content. Expand internal AI research agents to new geographic markets and adapt them to local data conditions. Develop evidence collection and reasoning logic for new place-related attributes. Evaluate ML systems across different locales, languages, and data sources. Improve pipeline orchestration and optimize multi-source data ingestion processes. Collaborate with cross-functional international teams to deliver scalable AI solutions. Requirements 5+ years of commercial experience in Data Engineering, Machine Learning, AI, or Data Science ( 7+ years preferred ). Strong Python programming skills, including Polars and/or Pandas . Commercial experience with Spark (Scala is a strong plus). Hands-on experience building and optimizing large-scale data pipelines. Experience with NLP and fine-tuning lightweight machine learning models. Good understanding of data quality, model evaluation, and ML performance metrics. Familiarity with agent frameworks, especially LangGraph . Experience adapting AI/ML solutions across multiple countries, languages, or data domains. Experience with pipeline orchestration and large-scale data processing. Strong analytical mindset, ownership, and problem-solving skills. Comfortable working in a dynamic, international environment. Nice to Have Commercial experience with Scala. Experience working with AI agents or LLM-based solutions. Background in large-scale web data processing. Experience supporting multi-market AI products.