Senior Machine Learning Data Scientist

Extend

Senior ML Data Scientist at Extend developing machine learning models for fraud detection and risk assessment. Collaborating with cross-functional teams to enhance post-purchase protection using AI.

Posted 5/15/2026full-timeRemote • California • 🇺🇸 United StatesSenior💰 $135,000 - $165,000 per yearWebsite

Tech Stack

Tools & technologies

PythonPyTorchScikit-LearnSQL

About the role

Key responsibilities & impact

Own the model lifecycle: requirements, experimentation, model development, evaluation, and model cards, partnering with ML engineers on deployment and production infrastructure
Translate complex fraud patterns into well-framed ML solutions: defining what to model, what success looks like, and where ML adds value vs. simpler approaches
Design and maintain feature engineering pipelines for model development
Monitor model quality in production, tracking performance over time, detecting data drift, and determining when to retrain
Partner closely with leadership, go-to-market, fraud operations, product, and engineering teams to define and execute effective fraud strategies
Champion a culture of continuous learning, experimentation, and collaboration across the fraud and broader data science teams

Requirements

What you’ll need

Hands-on, proactive, and analytical professionals who are passionate about using data to solve complex, real-world problems
Bachelor’s degree or higher in a quantitative field such as Mathematics, Statistics, Computer Science, Engineering, Operations Research, Physics or related field
3+ years of work experience building and deploying machine learning systems into production
Strong proficiency in Python and SQL
Strong understanding of ML fundamentals: model selection, evaluation methodology, feature engineering, and common failure modes
Hands-on experience with PyTorch, scikit-learn, and XGBoost (or similar gradient boosting frameworks)
High attention to detail, strong intellectual curiosity, and a deep understanding of user behavior and fraud patterns
Empathetic, humble, and collaborative team player
Candidates must be located within the continental United States

Benefits

Comp & perks

Competitive salary based on experience, with full medical and dental & vision benefits.
Stock in an early-stage startup growing quickly.
Generous, flexible paid time off policy.
401(k) with Financial Guidance from Morgan Stanley.

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

machine learningmodel developmentfeature engineeringmodel evaluationdata drift detectionPythonSQLmodel selectionscikit-learnXGBoost

Soft Skills

analyticalproactiveattention to detailintellectual curiositycollaborativeempathetichumbleteam player