# Senior Machine Learning Engineer, Risk Modeling

**Company:** [Square](https://hotfix.jobs/companies/square)
**Location:** San Francisco, CA
**Role:** ML Engineering
**Experience:** 8+ years
**Skills:** Python, NumPy, pandas, scikit-learn, Xgboost, PyTorch, TensorFlow, Pyspark, MLflow, Airflow, GCP, AWS, Snowflake, MySQL
**Posted:** 2026-06-22

> Senior ML Engineer building and deploying production risk and fraud detection models at scale for Cash App and Square. Owns end-to-end ML systems and partners cross-functionally to reduce financial loss.

## Job Description

## Responsibilities
- Partner with product, engineering, data science, policy, and operations to design and productionize ML-driven risk solutions at scale
- Own end-to-end machine learning systems — from problem definition and modeling to deployment, monitoring, and iteration
- Lead technical decision-making within your workstreams and influence ML strategy and planning
- Build tooling and processes that improve the speed, reliability, and impact of the ML development lifecycle
- Apply state-of-the-art modeling techniques and third-party data sources to improve detection and decision-making
- Investigate emerging fraud, abuse, and risk patterns to proactively inform product safeguards and policy
- Collaborate closely with ML platform and engineering teams to ensure models operate reliably in real time and at scale

## Requirements
- 8+ years of industry experience in machine learning, applied AI, or related fields
- Bachelor’s degree in a quantitative field (Computer Science, Engineering, Statistics, Physics, Applied Math); Master’s or PhD preferred
- Proven experience independently designing, deploying, and maintaining ML solutions in production
- Strong familiarity with techniques such as tree-based models, deep learning, transfer learning, or reinforcement learning
- Experience influencing technical direction and collaborating with cross-functional partners at scale
- Strong communication skills, sound judgment, and an ownership mindset

## Technologies
- Python (NumPy, Pandas, scikit-learn, XGBoost, PyTorch, TensorFlow/Keras)
- PySpark, MLflow, workflow orchestration tools (Airflow, Prefect)
- GCP (Vertex AI), AWS
- Snowflake, MySQL, Tableau, Mode
- Containerization, CI/CD, and production ML best practices

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**Apply:** https://hotfix.jobs/jobs/4a979bc0-99c6-457d-8524-6fac851c8e67
**Canonical:** https://hotfix.jobs/jobs/4a979bc0-99c6-457d-8524-6fac851c8e67