Senior Data Scientist

O projekcie: Who We Are While Xebia is a global tech company, our journey in CEE started with two Polish companies – PGS Software, known for world-class cloud and software solutions, and GetInData, a pioneer in Big Data. Today, we’re a team of 1,000+ experts delivering top-notch work across cloud, data, and software. And we’re just getting started. What We Do We work on projects that matter – and that make a difference. From fintech and e-commerce to aviation, logistics, media, and fashion, we help our clients build scalable platforms, data and AI solutions, and cutting-edge applications to shape the future of tech. Our clients include McLaren, Aviva, Deloitte, Spotify, Disney, ING, UPS, Tesco, Truecaller, AllSaints, Volotea, Schmitz Cargobull, Allegro, InPost, and many, many more. We value smart tech, real ownership, and continuous growth. We use modern, open-source stacks, and we’re proud to be trusted partners of Databricks, dbt, Snowflake, Azure, GCP, and AWS. Fun fact: we were the first AWS Premier Partner in Poland! Beyond Projects What makes Xebia special? Our community. We support tech communities, organize meetups (Software Talks, Data Tech Talks), and have a culture that actively support your growth via Guilds, Labs, and personal development budgets — for both tech and soft skills. It’s not just a job. It’s a place to grow. What sets us apart?  Our mindset. Our vibe. Our people. And while that’s hard to capture in text – come visit us and see for yourself. Wymagania: - ready to join within 2 weeks, - strong experience in applied data science and machine learning on real world datasets, - solid understanding of ranking, optimisation, or recommendation problems, - experience working with transactional and behavioural data, - proficiency in Python for data analysis and model development, - experience with experimentation, validation, and performance measurement of ML models, - understanding of overfitting, bias, and model generalisation, - ability to work closely with engineers to deploy models into production environments, - practical experience using AI-powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision-making in software delivery, - exposure to Snowflake based analytics or ML workflows. Work from the European Union region and a work permit are required. Nice to have: - experience working in environments with business KPI guardrails such as margin, conversion, or NPS, - experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work. Codzienne zadania: - analysing large scale search, booking, and behavioural datasets to identify patterns impacting conversion, margin, and user relevance, - designing, training, validating, and iterating machine learning models for ranking and recommendation use cases, - developing margin aware, conversion aware, and relevance based scoring models aligned with defined business KPIs, - experimenting with semantic relevance and embedding based approaches for intent driven search, - defining features, evaluating data quality, and collaborating on feature readiness for ML training, - runing and interpreting offline evaluations and online experiments, including A B testing and shadow mode validation, - monitoring model performance, data drift, and retraining needs in production, - collaborating closely with data engineers and platform engineers to productionise models and ensure scalability, - documenting assumptions, results, and trade offs to support knowledge transfer and long term maintainability.