Senior Data Scientist

About the Position

We are seeking a Senior Data Scientist with 5+ years of experience in machine learning and data science to join our team in Ukraine or Poland. You will focus on fraud detection and customer outcomes, using data science and machine learning to improve our Digital Trust & Safety platform.

Responsibilities

• Analyze fraud patterns, customer behavior, and model outcomes to identify opportunities for product and model improvements.
• Partner with engineering and product teams to define evaluation metrics, investigate gaps in current product behavior, and propose practical improvements that drive customer value.
• Design and run experiments on features, modeling approaches, and datasets to validate ideas and improve model performance.
• Evaluate model quality through dataset analysis, error analysis, calibration, and score distribution investigations.
• Build repeatable analyses, prototypes, and internal tools that support research, diagnosis, and operational decision-making.
• Communicate findings and recommendations clearly across data science, engineering, and business stakeholders.

Requirements

• Bachelor’s degree in Computer Science, Statistics, Mathematics, a related technical field, or equivalent practical experience.
• 5+ years of relevant industry experience in data science, machine learning, analytics, or a closely related field.
• Strong foundation in machine learning and data science best practices, with experience applying them to real-world problems.
• Experience working with large datasets using tools such as Python, Jupyter, Pandas, PySpark, scikit-learn, PyTorch, TensorFlow, or similar technologies.
• Comfort performing both deep analysis and lightweight prototyping to test ideas quickly.
• Strong problem-solving skills and the ability to work effectively in ambiguous spaces with competing priorities.
• Clear communication and collaboration skills, with a team-first mindset.

Nice to Have

• Experience in fraud, risk, trust and safety, cybersecurity, or adjacent domains.
• Familiarity with Java or another object-oriented programming language.
• Experience partnering closely with software engineers to productionize analytical or machine learning improvements.

We Offer

• Opportunity to work in a forward-thinking team that challenges the status quo.
• Collaborative environment that values open and constructive feedback.
• Deep commitment to learning, rigor, and impact.
• Competitive salary and benefits.

About the Company

Sift is the AI-powered fraud platform securing digital trust for leading global businesses. Our deep investments in machine learning and user identity, a data network scoring over 1 trillion events per year, and a commitment to long-term customer success help customers grow fearlessly while delivering safer, more seamless consumer experiences.

Headquarter: San Francisco, California

Founded: 2011

Size: 201-500 employees

Our mission is to help everyone trust the global network.

Meet Your Future Colleagues

Got interested? Apply right now!

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