Senior ML Fraud Engineer — Real-Time Risk

Affirm; United States; Remote; USD 110,000 - 153,000; Full time

Benefits offered by this job

Health coverage for you and dependents

ESPP equity rewards

Remote-first policy

Job summary

Affirm is transforming credit to be honest and friendly. The ML Fraud team builds real-time decision systems that protect customers and merchants while balancing fraud loss and conversion.

As a senior ML engineer, you will lead development of fraud models, scale feature pipelines, and productionize models with robust monitoring. You’ll collaborate across Engineering, Fraud Analytics, Product, and ML Platform in a remote Canada context.

Qualifications

• 6+ years experience researching, training, tuning and launching ML models at scale. PhD counts for up to 2 years.
• Track record of delivering high impact ML models in a low latency live setting.
• Strong Python skills and production-quality code.
• Experience building models for tabular classification (LightGBM / XGBoost / CatBoost).
• Experience with PyTorch.
• Experience with distributed processing (Spark).
• Experience with ML lifecycle tooling (Kubeflow, Airflow, MLflow).
• Proficient with AI-powered dev tools to accelerate iteration.

Responsibilities

• Lead development of new fraud prediction models for tabular, graph, and behavioral data.
• Build and scale feature pipelines and training datasets with internal and external signals.
• Prototype modeling ideas, run offline experiments, and push top approaches to production with risk controls.
• Productionize models into batch and real-time decision systems, improving latency and reliability.
• Instrument and monitor model and data health and define retraining and backtesting workflows.
• Identify foundational improvements to model-building processes.
• Collaborate with Engineering, Fraud Analytics, Product, and ML Platform to define requirements and communicate results clearly.

Skills

Python

production-quality code

low latency

ML model deployment

model monitoring

data pipeline

communication

ownership/growth mindset

Tools

LightGBM

XGBoost

CatBoost

PyTorch

Spark

Ray

Dask

Kubeflow

Airflow

MLflow

Claude Code / Cursor

Job description

Affirm is transforming credit to be honest and friendly. The ML Fraud team builds real-time decision systems that protect customers and merchants while balancing fraud loss and conversion.

As a senior ML engineer, you will lead development of fraud models, scale feature pipelines, and productionize models with robust monitoring. You’ll collaborate across Engineering, Fraud Analytics, Product, and ML Platform in a remote Canada context.