Senior Data Scientist (f/m/x)

Sii Poland; Warszawa; On-site; PLN 180,000 - 320,000; Full time

Benefits offered by this job

Great place to work

Profit sharing

Centre of internal trainings

Medical care

Open and accessible management team

Job summary

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

Responsibilities include owning the linking pipeline end-to-end, applying graph ML techniques, and ensuring data quality across sources in production-grade Python environments.

Qualifications

• 5+ years of production ML or data science experience with entity linking at scale.
• Strong Python with production-grade, tested, type-hinted code.
• SQL proficiency and experience with FastAPI, Docker, pytest, Git, and CI/CD.

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 scoring and calibrated probabilities.
• Define link quality metrics: precision, recall, calibration, error analysis.
• Link entities to controlled medical vocabularies for consistency.
• Use graph representations and graph ML for linking: clustering, centrality, link prediction.
• Build and maintain the data and graph estate, including ETL transformations.
• Improve algorithms to adapt to changing data sources and volumes.

Skills

Python

SQL

FastAPI

Docker

pytest

Git

CI/CD

Entity linking

Graph ML

GNNs

ETL

Data-quality monitoring

Tools

Neo4j

Amazon Neptune

Snowflake

BigQuery

Databricks

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