Data Science Tech Lead - Hands-on + Mentoring

Sii Poland; Łódź; On-site; PLN 180,000 - 280,000; Full time

Benefits offered by this job

AI Grants & Center of Excellence

Job summary

Sii Poland is seeking a technical lead to steer data science engagements end-to-end, from problem framing with clients to modeling approach sign-off and production delivery.

The role blends mentorship with hands-on coding in Python and direct influence on standards across platforms like Microsoft Fabric, Palantir Foundry, and Databricks. Fluent English and Polish are required, with residency in Poland.

Qualifications

• 6+ years in data science with a track record of models shipped to production; at least 2 years leading or mentoring others
• Hands-on Python across the standard data stack (pandas, NumPy, scikit-learn, XGBoost) and ability to review/write the hard parts
• Strong statistical and ML foundations: experimental design, validation methodology, and judgement to spot fragile results
• Familiarity with at least one cloud/data platform: Azure, AWS, GCP, Snowflake, Databricks, Palantir Foundry
• Experience leading delivery in a client-facing/consulting context: scoping, estimation, and managing technical risk
• Strong communication skills to defend methodology to technical audiences and explain business impact to non-technical stakeholders
• Fluent English (written and spoken) and Fluent Polish; residing in Poland
• Residing in Poland required

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, and raising the bar on what is considered done
• Stay hands-on: prototype approaches, unblock hard modeling problems, contribute production-grade Python where it matters
• Translate client business problems into scoped, estimable data science workstreams and push back when a model is unnecessary
• Set and enforce engineering standards for reproducibility, experiment tracking, testing, and documentation
• Guide platform decisions across cloud/data ecosystems — Microsoft Fabric, Palantir Foundry, Databricks, Snowflake, and native cloud services
• Work with AI Architects, data engineers, and client stakeholders to align technical decisions with business outcomes and timelines
• Represent the team in front of clients: present results, defend methodology, and manage technical expectations

Skills

Python

Pandas

NumPy

Scikit-learn

XGBoost

Leadership

Mentoring

Communication

English

Polish

Tools

Microsoft Fabric

Palantir Foundry

Databricks

Snowflake

Azure

AWS

GCP

Job description

Sii Poland is seeking a technical lead to steer data science engagements end-to-end, from problem framing with clients to modeling approach sign-off and production delivery.

The role blends mentorship with hands-on coding in Python and direct influence on standards across platforms like Microsoft Fabric, Palantir Foundry, and Databricks. Fluent English and Polish are required, with residency in Poland.