Staff Machine Learning Engineer (Modeling), Bitcoin Risk

Block is one company built from many blocks, all united by the same purpose of economic empowerment. The blocks that form our foundational teams - People, Finance, Counsel, Hardware, Information Security, Platform Infrastructure Engineering, and more - provide support and guidance at the corporate level. They work across business groups and around the globe, spanning time zones and disciplines to develop inclusive People policies, forecast finances, give legal counsel, safeguard systems, nurture new initiatives, and more. Every challenge creates possibilities, and we need different perspectives to see them all. Bring yours to Block.
The Role
We're looking for an experienced Machine Learning Engineer to join our Risk Modeling team, focused on Bitcoin products. This team detects and responds to fraudulent and illicit Bitcoin activity across Cash App and Square.
You'll serve as the DRI for Bitcoin risk modeling-building end-to-end strategy, model development across Block's Bitcoin ecosystem. You'll operate with a high degree of autonomy, partnering closely with Product, Engineering, and Compliance to shape how risk and compliance controls scale as we launch new Bitcoin products.
You Will

• 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
• Mentor teammates and contribute to a strong, inclusive engineering culture

You Have

• 7+ 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
• Prior experience with Bitcoin or crypto is helpful, but not required
• Proven experience independently designing, deploying, and maintaining ML solutions in production
• Experience influencing technical direction and collaborating with cross-functional partners at scale
• Strong communication skills, sound judgment, and an ownership mindset
• Curiosity and alignment with Block's mission of economic empowerment

Technologies We Use and Teach

• 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

Block takes a market-based approach to pay, and pay may vary depending on your location. U.S. locations are categorized into one of four zones based on a cost of labor index for that geographic area. The successful candidate's starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future.
To find a location's zone designation, please refer to this resource . If a location of interest is not listed, please speak with a recruiter for additional information.
Zone A:
$276,800 - $415,200 USD
Zone B:
$276,800 - $415,200 USD
Zone C:
$276,800 - $415,200 USD
Zone D:
$276,800 - $415,200 USD
Application Guidelines
Candidates may submit up to 9 active applications within a 60-day period. Reapplications to the same role are accepted 90 days after a previous application has been reviewed.
Use of AI in Our Hiring Process
We may use automated AI tools to evaluate job applications for efficiency and consistency. These tools comply with local regulations, including bias audits, and we handle all personal data in accordance with state and local privacy laws.
Contact us here with hiring practice or data usage questions.
Every benefit we offer is designed with one goal: empowering you to do the best work of your career while building the life you want. Remote work, medical insurance, flexible time off, retirement savings plans, and modern family planning are just some of our offering. Check out our other benefits at Block.
Block, Inc. (NYSE: XYZ) builds technology to increase access to the global economy. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we're helping build a financial system that is open to everyone.