Machine Learning Engineer, Team Leader

Xebia sp. z o.o., located in Warszawa, is hiring for a Machine Learning Engineer Team Leader role focused on delivering high-quality ML Scoring solutions such as click and conversion predictions. The company operates in data-related projects and requires cooperation with backend and product stakeholders for orchestration and transition of scoring responsibilities.

• 8+ years of experience in Machine Learning or Data Science roles in production environments.
• 2+ years of direct people management experience.
• Proven track record in leading end-to-end model training initiatives for business use cases.
• Strong practical expertise in the full model lifecycle: data preparation, feature engineering, training, evaluation, calibration, and controlled rollout.
• Hands-on proficiency in Python and SQL, with strong understanding of ML/deep learning frameworks (e.g., PyTorch or TensorFlow) and scalable data processing workflows.
• Experience operating ML workloads in cloud environments, preferably GCP (Vertex AI, BigQuery, Cloud Storage).
• Proven ability to drive cross-functional execution across ML, serving, and product domains, ensuring strategic alignment and performance visibility for stakeholders.
• Strong decision-making based on business impact metrics and experimentation results.
• Very good command of English, both written and spoken.
• Openness to on-site workshops max 1-3 per quarter in Warsaw.

Nice to have:

• Experience in AdTech, marketplace ranking, or recommendation systems at scale.
• Familiarity with model artifact repositories, CI/CD for ML, experiment tracking frameworks, and feature store integrations.
• Exposure to online inference environments and cooperation with platform teams maintaining such services.
• Experience with developing pCTR/pCVR-like models.

• Ensuring that the team delivers high-quality ML Scoring solutions on schedule.
• Maintaining responsibility for the team's technical output and project milestones.
• Managing the training scope for deep learning models, including feature space definition and model lifecycle standards.
• Orchestrating the transition of scoring responsibilities from existing teams in cooperation with backend and product stakeholders.
• Providing expert insight to future roadmaps for the ML scope.

Work from the European Union region and a work permit are required. Candidates must have an active VAT status in the EU VIES registry.