# Staff Machine Learning Engineer, Underwriting and Credit
**Company:** [Square](https://hotfix.jobs/companies/square)
**Location:** Remote
**Salary:** $277K-$415K
**Experience:** 10+ years
**Skills:** Python, NumPy, pandas, scikit-learn, PyTorch, Xgboost, Lightgbm, MLflow, Prefect, Airflow, SQL, Snowflake, GCP, AWS
**Posted:** 2026-06-15
> Senior IC building and maintaining ML underwriting and credit decisioning models for Cash App Borrow and Afterpay. Owns full modeling lifecycle including experimentation, calibration, deployment, and monitoring.
## Job Description
## Responsibilities
- Build, evaluate, and maintain underwriting and decisioning models across Cash App Borrow and Afterpay.
- Design and evolve credit decision frameworks, including the modeling, automation, and policy logic that manage credit exposure over time.
- Design and run experiments to evaluate model performance, measure impact on approval rates and loss, and inform credit policy decisions.
- Develop deep understanding of borrower behavior, repayment dynamics, and portfolio structure across both products, and use that to inform model design and decision logic.
- Contribute analysis and perspective that inform portfolio-level decisions, including explaining model behavior, tradeoffs, and uncertainty to senior technical and business leaders.
- Work across the full modeling lifecycle: problem formulation, feature engineering, training, calibration, deployment, monitoring, and iteration in production.
- Build agentic engineering workflows that accelerate development, testing, and documentation.
- Collaborate with Product, Engineering, Legal, Compliance, and Operations to ensure credit systems reflect business goals and regulatory expectations.
- Share modeling context and approaches across teams, helping align how credit risk is measured, interpreted, and discussed.
- Shape how AI developer tooling is adopted across the team, defining review practices, quality standards, and governance patterns.

## Requirements
- Bachelor's degree in a quantitative field (e.g., Mathematics, Statistics, Physics, Computer Science). Advanced degrees welcome.
- 10+ years applying AI, machine learning, or statistical modeling in decisioning contexts such as credit, risk, fraud, recommendations, or similar domains.
- Experience with probabilistic models and decision systems, including calibration, score transformations, and interpretation of model outputs.
- Strong experimentation skills: design holdouts, measure lift, and evaluate models beyond aggregate metrics.
- Experience with model monitoring, degradation detection, and retraining strategies in production systems.
- Proficiency with AI-native development workflows using LLMs, agentic coding tools, and AI-assisted automation.
- Experience explaining modeling concepts, results, and limitations to senior stakeholders and cross-functional partners.
- Experience working across disciplines in environments with meaningful constraints.

## Technologies
- Python (NumPy, Pandas, scikit-learn, PyTorch, XGBoost, LightGBM)
- AI development tools: Claude Code, Cursor, Copilot
- MLflow for experiment tracking and model registry
- Internal feature store and model hosting platform
- Prefect and Airflow for orchestration
- SQL / Snowflake
- GitHub
- GCP / AWS
**Apply:** https://hotfix.jobs/jobs/staff-machine-learning-engineer-underwriting-and-credit-at-square-b61761e2-2aef-46fd-888b-9f738b8c47f2
**Canonical:** https://hotfix.jobs/jobs/staff-machine-learning-engineer-underwriting-and-credit-at-square-b61761e2-2aef-46fd-888b-9f738b8c47f2