Senior Data Scientist (f/m/x)

Sii Poland; Wrocław; On-site; PLN 260,000 - 360,000; Full time

Job summary

Sii Poland is seeking a Senior Data Scientist to join an AI-driven operating system for healthcare marketing. You will design and implement entity extraction, linking, and resolution at scale, reconciling large and fragmented datasets into reliable entities and attributes.

You will own the linking pipeline end-to-end, apply probabilistic scoring, and validate quality using precision, recall, calibration, and error analysis while aligning with controlled medical vocabularies.

Qualifications

• 5+ years of production ML or data-science experience.
• Hands-on entity linking and resolution at scale.
• Production-grade Python with typing in code.
• Strong SQL, FastAPI, Docker, pytest, Git, CI/CD knowledge.
• Experience with probabilistic methods for match scoring and calibration.
• Graph ML and embeddings experience.

Responsibilities

• Extract entities and attributes from heterogeneous sources.
• Design probabilistic entity linking and deduplication across large healthcare datasets.
• Own the linking pipeline end to end with graph-based scoring.
• Define link quality metrics: precision, recall, calibration, error analysis.
• Link entities to controlled medical vocabularies for consistency.
• Apply graph representations and ML techniques for linking and clustering.
• Maintain data and graph estates including ETL transformations.
• Improve algorithms as data sources evolve.

Skills

Entity linking

Graph ML

ML engineering

Python

SQL

Data quality

Embeddings

GNNs

Tools

FastAPI

Docker

pytest

Git

CI/CD

Snowflake

BigQuery

Databricks

Neo4j

Amazon Neptune

Job description

We are looking for a Senior Data Scientist to join a project focused on building an AI-powered operating system for healthcare marketing. In this role, you will design and implement entity extraction, linking, and resolution at scale, reconciling large and fragmented datasets into reliable entities and attributes. You will work on production-grade products that create real value in the life sciences industry, ensuring the integrity and quality of the data used for audience reach and insights.

Your tasks

• Extracting entities and attributes from heterogeneous sources including warehouse tables, registries, and documents
• Designing and implementing probabilistic entity linking and deduplication across multiple large healthcare datasets
• Owning the linking pipeline from end to end, including pairwise and graph-based scoring and calibrated match probabilities
• Defining how link quality is measured through precision, recall, calibration, and error analysis
• Linking entities and attributes to controlled medical vocabularies to ensure consistency across sources
• Utilizing graph representations and graph ML techniques for linking, including clustering, centrality, and link prediction
• Building and maintaining the data and graph estate, including warehouse transformation and monitoring
• Improving the performance of existing algorithms in response to changing data sources and volumes

Requirements

• Minimum 5 years of experience in shipping production ML or data-science work, including hands-on entity linking and resolution at scale
• Deep expertise in Python, including production-grade, tested, and type-hinted code
• Strong command of SQL and experience with FastAPI, Docker, pytest, Git, and CI/CD practices
• Practical experience in probabilistic methods for match scoring, threshold selection, and evaluation
• Comfort with graph algorithms and graph ML techniques, including embeddings and GNNs
• Experience with data and ML engineering, including ETL processes over large datasets and data-quality monitoring
• Familiarity with distributed SQL warehouses such as Snowflake, BigQuery, or Databricks, and graph technologies like Neo4j or Amazon Neptune
• Advanced level of English

Job no. JOB-C3836

Sii ensures that all hiring decisions are made solely on the basis of qualifications and competence. We are committed to equal and fair treatment of all, regardless of legally protected characteristics. At Sii, we promote a diverse and inclusive work environment, in full compliance with applicable anti-discrimination laws.

Benefits For You

• Great Place to Work
• Solid financial situation
• Contracts with the biggest brands
• Centre of internal trainings
• Many experts you can learn from
• Open and accessible management team
• Profit sharing
• Passion Sponsorship program
• Regular integration events and trips
• Comfortable and well-equipped offices
• MySii app
• Medical care