Senior Data Scientist

Project description:

Our client is one of the largest e-commerce platforms in Europe, used by millions of users every day. The company connects sellers - from small businesses to global brands - with customers, offering a vast product selection, fast delivery, and a well-crafted shopping experience.

The role:

• Senior Data Scientist specializing in ML Models for Advertising and Ranking Domains.
• Drive the design, refinement, and evaluation of ML scoring models (e.g., CTR, CVR, and RoAS), integral to core bidding logic.
• Architect model strategies for complex solutions integrating user, product, and placement signals, ensuring readiness for high-throughput and low-latency environments.
• Partner with engineering and business stakeholders to translate strategic goals into measurable modeling outcomes and technical roadmaps.
• Provide technical leadership and quality assurance for Data Science workstreams within the project scope to ensure alignment with production standards.

Specific skills and tools

Python, PyTorch, TensorFlow, SQL (BigQuery), Docker, GCP, Vertex AI, Vertex Pipelines, Deep Learning, Experiment Design, and Low-Latency Model Development.

• Extensive hands-on experience in designing, training, and improving Deep Learning models for business-critical production use cases.
• Proven expertise in deep learning frameworks such as PyTorch or TensorFlow, as well as strong practical knowledge of Pandas and NumPy.
• Advanced SQL skills, preferably including analytical SQL used in large-scale data environments.
• Strong experience with public cloud infrastructure, preferably Google Cloud Platform, including ML- oriented services such as Vertex AI and Vertex Pipelines.
• Proven ability to lead end-to-end model development, from problem framing and feature design to evaluation and production handoff.
• Strong engineering foundations, including writing production-level, testable, and documented Python code, with familiarity with CI/CD practices.
• Ability to mentor other Data Scientists and raise modeling standards across the team.
• Relevant academic degree or extensive professional experience in a STEM field (e.g. Computer Science, Mathematics, Mathematical Statistics, Quantitative Methods, or Physics).
• English level min. B2.

Nice to have:

• Experience in developing ML models for low-latency online applications.
• Experience within the advertising or marketing domains.
• Demonstrated experience in developing ML models for predicting business events like clicks or conversions (i.e., Click-Through Rate (CTR) and Conversion Rate (CVR) modelling).
• Proficiency in traditional machine learning techniques, such as Gradient Boosted Trees.
• Experience in mentoring, technical leadership, or coordinating model development across a broader team.
• Practical use of AI-assisted coding tools to improve engineering productivity and quality.

Recruitment process:

• 30-minute screen with our recruiter, Justyna
• Profile screening by Manager
• Client Technical Verification Meetings
• Stakeholder meeting
• Offer