Senior Machine Learning Engineer (Fraud ML)

About the Role: Affirm is reinventing credit to make it more honest and friendly. On the ML Fraud team, you'll build and improve machine learning systems that make real-time transaction decisions, protecting consumers and merchants while balancing fraud loss, customer experience, and conversion.

What You'll Do

• Lead the development of new fraud prediction models using a mix of approaches for tabular, graph, and behavioral data.
• Build and scale feature pipelines and training datasets from proprietary and third-party signals.
• Productionize models by integrating them into batch and/or real-time decision systems.
• Instrument and monitor model and data health, defining retraining/backtesting workflows as fraud patterns evolve.
• Collaborate across Engineering, Fraud Analytics, Product, and ML Platform teams.

What You Bring

• 6+ years of experience researching, training, tuning, and launching ML models at scale.
• Strong Python skills and experience writing production-quality code.
• Experience building models for tabular classification problems (LightGBM/XGBoost/CatBoost).
• Experience with deep learning frameworks (PyTorch preferred) and distributed data processing (Spark preferred).
• Experience with ML lifecycle tooling (e.g., Kubeflow, Airflow, MLflow).

Benefits

• Base pay range of $150,000 - $200,000 CAD per year, plus eligible equity rewards.
• 100% subsidized medical coverage, dental, and vision for you and your dependents.
• Flexible Spending Wallets for technology, food, lifestyle needs, and family forming expenses.
• Remote-first culture with the flexibility to work almost anywhere within Canada.