We are looking for a Staff Data Scientist to join a Growth Alliance team at the Tech Lead level. This role goes beyond hands-on data science, it requires a candidate who can set technical direction, lead complex ML initiatives, and act as a strategic partner to business stakeholders. You will operate at the intersection of advanced machine learning, real-time systems, and product growth.

About the Project:
This is a Staff / Tech Lead position within a team driving AI-powered decisioning at scale. You will work on systems with strict real-time constraints (<40 ms latency) that directly impact end-user experience and conversion. The mission is to move the product toward AI-driven decisioning, targeting a measurable improvement in conversion (~5%). You will be expected to challenge assumptions, define the technical roadmap, and ensure that ML systems perform reliably in production.

Responsibilities:

• Lead the design and implementation of production ML systems, including real-time decisioning and personalization engines;
• Drive adoption of contextual bandits, uplift modeling, and advanced recommendation frameworks;
• Define experimentation strategy including A/B testing, causal inference, and synthetic controls;
• Oversee feature engineering at scale and ensure robust model monitoring and validation practices;
• Act as a technical owner for decisioning platforms and Martech integrations;
• Collaborate with and influence senior business stakeholders to shape data science strategy;
• Guide and mentor other data scientists on the team;
• Lead GenAI and LLM-based initiatives including fine-tuning, evaluation, and content personalization.

Qualifications:

• 10+ years of experience in Data Science, with a strong track record in production ML systems;
• Expert-level Python (NumPy, Pandas, Scikit-learn) and SQL;
• Deep experience with PySpark / Apache Spark for large-scale data processing;
• Mastery of gradient boosting methods (XGBoost, LightGBM), recommendation systems, NLP, clustering, and uplift modeling;
• Extensive experience with A/B testing, causal inference, statistical modeling, and synthetic controls;
• Proven ability to build and maintain production ML pipelines on cloud platforms (AWS preferred);
• Experience with decisioning platforms, personalization engines, and Martech integrations;
• Hands-on experience with LLMs, prompt engineering, evaluation, and fine-tuning;
• Strong stakeholder management skills with the ability to challenge assumptions and ask the right questions;
• Databricks experience is a nice to have.

Recruitment Process:

• Initial interview with our recruitment team;
• Interview with the hiring manager;
• Live Coding Assessment;
• Meeting with the Project Manager.

Inuits Sp. z o.o. is registered in the National Register of Employment Agencies (KRAZ) under number 35420.