Senior Machine Learning Engineer, Model Risk Management

Block is looking for a Senior Machine Learning Engineer to lead model risk validation across lending, fraud, and AML. You will build agentic validation tooling, evaluate GenAI systems, and set standards for production AI. This senior IC role involves independent challenge of ML models and cross-team collaboration.

• Independently challenge model owners across lending, fraud, and AML: reproduce results, set acceptance thresholds, and own the soundness call.
• Hunt silent errors that make metrics lie and prove them out before production.
• Build agentic validation tooling orchestrating agents in parallel.
• Reason about ML systems end to end and tie explainability findings to model decisions.
• Help define validation standards for frontier production AI.

• Quantitative degree or equivalent senior-IC depth in a high-stakes ML domain (credit, fraud, financial crime).
• Command of effective-challenge methodology: reproduction, conceptual-soundness review, benchmarking, stress testing, outcomes analysis.
• Deep applied ML and statistics across regression, tree ensembles, deep learning.
• Experimentation and statistical rigor: holdout design, uncertainty reasoning.
• Solid software and data engineering: production Python, SQL on large datasets.