Data Science Tech Lead — Hands-on, Mentoring & Delivery

Sii Poland; Kraków; On-site; PLN 300,000 - 420,000; Full time

Benefits offered by this job

Great Place to Work

Financial stability

Brand contracts

Internal trainings

Mentor network

Open management

Profit sharing

Sponsorship program

Team events

Modern offices

MySii app

Medical care

Job summary

Sii Poland is seeking a technical lead for data science who can steer end-to-end engagements from framing problems to sign-off on modeling approaches. The role combines hands-on Python work with leadership, standards setting, and client-facing delivery across major cloud and data platforms.

You will mentor a team of data scientists, review methodology, and ensure reproducible, production-grade outcomes while collaborating with AI architects and engineers.

Qualifications

• 6+ years in data science with production models.
• Minimum 2 years leading or mentoring data scientists.
• Hands-on Python plus core data stack (pandas, NumPy, scikit-learn, XGBoost).
• Cloud/data platform experience: Azure, AWS, or GCP; Snowflake/Databricks/Foundry familiarity.
• Strong communication, able to defend methods to technical and non-technical audiences.
• Fluent English and Polish; residing in Poland.

Responsibilities

• Own the technical direction of data science engagements: solution design, modeling approach, validation strategy, and delivery quality.
• Lead and mentor a team of data scientists — code reviews, methodology reviews, career development.
• Stay hands-on: prototype approaches and contribute production-grade Python where it matters.
• Translate client business problems into scoped, estimable data science workstreams.
• Set and enforce engineering standards: reproducibility, experiment tracking, testing, documentation.
• Guide platform decisions across cloud/data ecosystems (Fabric, Foundry, Databricks, Snowflake, Azure/AWS/GCP).
• Collaborate with AI Architects, data engineers, and client stakeholders to align tech with business outcomes.
• Represent the team to clients: present results and defend methodology.

Skills

6+ years data science

2+ years leadership

Python

Pandas

NumPy

scikit-learn

XGBoost

Cloud platforms

Communication

Fluent English

Fluent Polish

Poland resident

Tools

Azure

AWS

GCP

Databricks

Snowflake

Palantir Foundry

Microsoft Fabric

Job description

Sii Poland is seeking a technical lead for data science who can steer end-to-end engagements from framing problems to sign-off on modeling approaches. The role combines hands-on Python work with leadership, standards setting, and client-facing delivery across major cloud and data platforms.

You will mentor a team of data scientists, review methodology, and ensure reproducible, production-grade outcomes while collaborating with AI architects and engineers.