Senior Data Scientist, Risk and Fraud Management, Growth Alliance

Technologies we use

Your responsibilities

• Work on fraud detection and risk assessment models from data collection to production, collaborating closely with cross-functional teams (engineering, product, finance, operations)
• Build, deploy, and maintain machine learning models for:
• Ship & Collect: Offline batch inference for recurring payment risk assessment and subscription fulfillment decisions
• Voucher Fraud Prevention: Real-time inference at checkout to detect and prevent voucher abuse patterns
• Payment Fraud Prevention: Real-time inference at checkout to detect and block fraudulent payment attempts
• Monitor model performance, detect anomalies, and communicate insights and recommendations to technical and non-technical stakeholders
• Leverage classification, regression, and uplift methodologies to continuously improve fraud prevention and risk assessment solutions
• Proactively utilize Generative AI tools to accelerate development cycles, improve code quality, and drive innovative solutions to complex challenges

Our requirements

• Bachelors, Masters or PhD in statistics, physics, economics, mathematics, computer science, data science or similar
• 3+ years work experience as a (senior) data scientist, preferably in e-commerce, fintech, or fraud detection
• Strong experience with classification and regression models; familiarity with uplift modeling is a plus
• Fluency in Python (Numpy, Pandas, Scikit-learn, XGBoost, LightGBM) and experience with Spark/PySpark, Databricks
• Experience with AWS services (SageMaker), workflow orchestration (Airflow/Prefect), and feature stores (Tecton is a plus)
• In-depth knowledge of handling imbalanced datasets, optimizing precision/recall trade-offs, and evaluating models in production
• Experience with real-time model inference, A/B testing, and measuring business impact of ML models
• Familiarity with software development practices (Git, Docker, CI/CD pipelines)
• Strong communication and collaboration capabilities with technical and non-technical stakeholders

What we offer

• Global collaboration at scale: Collaborate with experienced engineers and product partners across HelloTech’s international teams, in a culture of active knowledge sharing.
• Technology with real-world impact: Build and operate modern systems at global scale, supporting 6+ millions of customers and complex supply chain operations.
• Technical/Product/Design leadership: Drive best practices and influence architecture/design, quality, and ways of working in an autonomous, product-led setup.
• End-to-end development/delivery: Drive decisions from problem definition to production, improving systems and enabling long-term scalability.
• Access to workspace at Warsaw Centre Point. The hub offers modern facilities including showers, breakout zones, outdoor space, cycle parking, and refreshments (coffee, soft drinks, and fruit).

About the role: What's in the Box