Data Scientist – Python & Cloud Data Platforms (f/m/x)

Our requirements

• At least 4 years in data science or applied analytics, with models and analyses that made it past the prototype stage
• Strong Python skills across the standard data stack (pandas, NumPy, scikit-learn)
• Solid statistical foundations: hypothesis testing, regression, experimental design, and knowing when a result is real versus noise
• Knowledge of at least one cloud/data platform and its data science components — Azure (Microsoft Fabric, Azure Machine Learning), AWS (SageMaker), GCP (Vertex AI, BigQuery ML), Snowflake (Snowpark ML, Cortex), Databricks (MLflow, Mosaic AI), or Palantir (Foundry Code Workspaces, Foundry ML, AIP)
• Ability to communicate analytical results clearly to business stakeholders and influence decisions with data
• Familiarity with working autonomously while collaborating effectively with data engineers, architects, and product teams
• Fluent English, both written and spoken
• Fluent Polish required
• Residing in Poland required

Optional

• Production experience with Microsoft Fabric or Palantir Foundry certification (Foundry Data Engineer / Data Scientist tracks)
• Experience with time series forecasting, NLP, recommender systems, or exposure to LLM-based workflows
• Familiarity with MLOps practices: MLflow, experiment tracking, model versioning, and CI/CD for ML
• Experience with Power BI or other BI tools, and distributed processing with Spark/PySpark

Your responsibilities

• Translate business problems into analytical solutions: define hypotheses, choose metrics, and select the right modeling approach for the question at hand
• Explore, clean, and prepare data using Python (pandas, NumPy), working with structured and semi-structured sources of varying quality
• Build, validate, and tune machine learning models for classification, regression, forecasting, segmentation, and recommendation using scikit-learn, XGBoost, and statsmodels
• Design and analyze experiments: A/B tests, statistical hypothesis testing, and causal analysis that hold up to scrutiny
• Work hands-on with enterprise data platforms such as Microsoft Fabric (lakehouses, notebooks, semantic models) and Palantir Foundry (pipelines, ontology, operational workflows)
• Communicate findings through clear visualizations, dashboards, and narratives tailored to technical and non-technical stakeholders alike
• Collaborate with data engineers on data availability and quality, and with ML/AI engineers to move models from notebook to production
• Monitor deployed models for drift and degradation, and own the retraining and improvement cycle

About the project

What we offer

• AI Grant — Stop talking about AI and start building it. Our AI Grant gives you dedicated budget and resources to turn your wildest AI idea into a working project, backed by two paid weeks to focus on nothing else.
• AI Center of Excellence — Work alongside specialists in agentic AI, sovereign AI, generative and discriminative AI. This isn’t a siloed team — it’s the people you’ll learn from and build with daily.
• Your tools, your choice — Full access to AI-powered development tools including Claude, Cursor, and GitHub Copilot. Pick what works best for you.
• Real project variety — From generative AI for legal document compliance, through agentic systems in manufacturing environments, to enterprise-scale AI platforms, computer vision, and autonomous driving. You won’t get bored.
• Conference and speaking support — Want to attend conferences? We’ll back you. Want to speak at them? Even better — we’ll support you with dedicated preparation time and bonuses.
• Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas
• Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market
• We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022
• Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more
• Comfortable workplace – class A offices or remote work
• Dozens of fascinating projects for prestigious brands from all over the world – you can change them thanks to Job Changer application
• PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers
• Investment in your growth – meetups, webinars, training platform and technology blog – you choose
• Fantastic atmosphere created by all Sii Power People

Recruitment stages

• 1.
  Send your CV
• 2.
  Talk to us about your expectations
• 3.
  Learn more about our projects and choose the best
• 4.
  Start your adventure with Sii!

Sii Sp. z o.o.