Technical Lead, Data Science — Hands-On & Mentoring

Sii Poland; Szczecin; On-site; PLN 250,000 - 420,000; Full time

Benefits offered by this job

Great Place to Work

Profit sharing

Centre of internal trainings

Many experts you can learn from

Open and accessible management team

Medical care

Job summary

Sii Poland is seeking a Technical Lead in Data Science in Poland. You will own end-to-end technical direction for data science engagements, framing problems with clients, and signing off on modeling approaches while ensuring delivery quality.

This is a hands-on role with mentorship responsibilities: you’ll write Python, review models, and guide the team across platforms like Microsoft Fabric, Palantir Foundry, Databricks, and major clouds. Fluent English and Polish are required.

Qualifications

• Minimum 6 years in data science with production-models shipped.
• At least 2 years leading or mentoring data scientists.
• Strong Python skills across the data stack and ability to review complex code.
• Solid statistical and ML foundations with experimental design and validation.
• Experience with at least one cloud/data platform (Azure, AWS, GCP, Snowflake, Databricks, Palantir).
• Client-facing delivery experience: scoping, estimation, risk management.
• Excellent written and spoken English; fluent Polish is required.

Responsibilities

• Own the technical direction of data science engagements: solution design, modeling approach, validation strategy.
• Lead and mentor a team of data scientists, conduct reviews, and raise the bar on deliverables.
• Stay hands-on by prototyping approaches and contributing production-grade Python where needed.
• Translate client problems into scoped, estimable data science workstreams and push back when not needed.
• Set engineering standards for reproducibility, experiment tracking, testing, and docs.
• Guide platform decisions across cloud/data ecosystems and align with business timelines.
• Collaborate with AI architects, data engineers, and stakeholders to ensure impact.
• Represent the team to clients, presenting results and defending methodologies.

Skills

Python

Data science

Mentoring

Team leadership

Cloud platforms

Communication

English

Tools

Pandas

NumPy

scikit-learn

XGBoost

Python tooling (CI/CD)

Job description

Sii Poland is seeking a Technical Lead in Data Science in Poland. You will own end-to-end technical direction for data science engagements, framing problems with clients, and signing off on modeling approaches while ensuring delivery quality.

This is a hands-on role with mentorship responsibilities: you’ll write Python, review models, and guide the team across platforms like Microsoft Fabric, Palantir Foundry, Databricks, and major clouds. Fluent English and Polish are required.