Senior Machine Learning Engineer, Model Risk Management

The Senior Machine Learning Engineer, Model Risk Management at Block is a pivotal role within the company's Model Risk Management team. This team is responsible for ensuring that models used in lending, fraud detection, and anti-money laundering (AML) are robust, reliable, and compliant with regulatory standards. Block, known for its innovative financial services like Square and Cash App, is committed to building a financial system that is open to everyone.

In this role, the engineer will independently assess and challenge model owners across various domains, including lending, fraud, and AML. Key responsibilities include reproducing model results, setting and defending acceptance thresholds, and determining the soundness of models before deployment. The engineer will also identify and address potential errors that could lead to inaccurate metrics, ensuring models perform reliably under real-world conditions. Additionally, the role involves developing validation tooling to support the team's efforts in overseeing advanced AI systems.

Candidates should possess a quantitative degree or equivalent experience, with a strong background in building or validating models in high-stakes domains such as credit, fraud, or financial crime. Proficiency in effective challenge methodologies, including reproduction, conceptual soundness review, benchmarking, stress testing, and outcomes analysis, is essential. A deep understanding of applied machine learning and statistics across various model families, from regression and tree ensembles to deep learning, is required. Experience with experimentation and statistical rigor, including holdout and experiment design, uncertainty reasoning, and evaluating models beyond aggregate accuracy, is also necessary. Solid software and data engineering skills, particularly in Python and SQL for large datasets, are important, as is familiarity with modern AI technologies like large language models (LLMs) and agentic tools. Knowledge of model risk management frameworks and fair-lending practices is advantageous.

While specific compensation details are not provided, Block offers a comprehensive benefits package designed to support employees' well-being and professional growth. This includes competitive salaries, health and wellness programs, flexible time-off policies, and opportunities for career advancement within the company.

Block fosters a culture of innovation, collaboration, and impact. Employees are encouraged to take ownership of their work, challenge the status quo, and contribute to the company's mission of economic empowerment. The company values diverse perspectives and provides a supportive environment for personal and professional development.