Machine Learning Engineer II (underwriting Ml)

Affirm Affirm · Fintech · Canada, United States · Remote · Checkout

Machine Learning Engineer II on the Underwriting ML team at Affirm, focusing on building and improving ML systems for real-time transaction decisions in a fintech context. Responsibilities include developing prediction models, scaling feature pipelines, prototyping new modeling ideas, productionizing models, and monitoring model/data health. Requires experience with Python, classification models (GBDTs, deep learning), distributed data processing, and ML lifecycle tooling.

What you'd actually do

  1. You will develop and iterate on underwriting prediction models using a mix of approaches for tabular and sequential data
  2. You will build and scale feature pipelines and training datasets from proprietary and third-party signals, partnering with data and platform teams when needed.
  3. You will prototype new modeling ideas and features, run offline experiments, and drive the best-performing approaches into production with appropriate risk controls.
  4. You will help productionize models: integrate into batch and/or real-time decision systems, and improve reliability, latency, and operational robustness.
  5. You will instrument and monitor model and data health, and help define retraining/backtesting workflows

Skills

Required

  • Python
  • classification models (gradient-boosted decision trees like LightGBM/XGBoost/CatBoost, or similar)
  • deep learning framework (PyTorch preferred)
  • distributed data processing or parallel compute frameworks (Spark preferred; Ray/Dask or similar)
  • ML lifecycle tooling for training orchestration, experimentation, and model monitoring (e.g., Kubeflow, Airflow, MLflow, or equivalent internal platforms)
  • taking a simple problem or business scenario into a solution that interacts with multiple software components, and executing on it by writing clear, easily understood, well tested and extensible code
  • navigating a large code base, debugging others' code, and providing feedback to other engineers through code reviews

Nice to have

  • PhD in a relevant field
  • PyTorch
  • Spark
  • Ray/Dask or similar
  • Kubeflow, Airflow, MLflow, or equivalent internal platforms
  • AI-powered developer tools (e.g., Claude Code, Cursor, or similar)

What the JD emphasized

  • production-quality code
  • productionize models
  • model monitoring
  • model health

Other signals

  • production models
  • real-time transaction decisions
  • feature pipelines
  • monitoring model health