Machine Learning Engineer (Modeling), Risk

Since we opened our doors in 2009, the world of commerce has evolved immensely, and so has Square. After enabling anyone to take payments and never miss a sale, we saw sellers stymied by disparate, outmoded products and tools that wouldn't work together.
So we expanded into software and started building integrated, omnichannel solutions - to help sellers sell online, manage inventory, offer buy now, pay later functionality, book appointments, engage loyal buyers, and hire and pay staff. Across it all, we've embedded financial services tools at the point of sale, so merchants can access a business loan and manage their cash flow in one place. Afterpay furthers our goal to provide omnichannel tools that unlock meaningful value and growth, enabling sellers to capture the next generation shopper, increase order sizes, and compete at a larger scale.
Today, we are a partner to sellers of all sizes - large, enterprise-scale businesses with complex operations, sellers just starting, as well as merchants who began selling with Square and have grown larger over time. As our sellers grow, so do our solutions. There is a massive opportunity in front of us. We're building a significant, meaningful, and lasting business, and we are helping sellers worldwide do the same.
The Role
Block's Chargeback Risk Machine Learning team members build machine learning models and systems to precisely detect, intervene on, and reduce fraudulent activity across Block's Cash App and Square ecosystems. As part of our team, you and your work will safeguard the Cash App and Square ecosystems from financial loss and provide trustworthy and seamless financial experiences for millions of customers and sellers.
You Will

• Partner with product, engineering, data science, policy, and operations to design and productionize ML-driven solutions to fight fraud at scale
• Become a risk domain expert and expert to lead strategy and planning on your workstreams.
• Develop tooling and processes to improve the effectiveness and speed of the ML development lifecycle
• Investigate and use state-of-the-art modeling algorithms and third-party data sources to boost model performance
• Contribute positively to our team culture as a collaborative, empathetic, and reliable teammate.

You Have

• 3+ years of machine learning experience
• A degree (preferably graduate level) in Computer Science, Engineering, Statistics, Physics, Applied Math or a related technical field
• Hands-on experience independently designing, deploying, and troubleshooting ML solutions using methods such as tree-based models, deep learning, transfer learning, or reinforcement learning.
• Proficiency in modern ML stacks such as: PySpark, PyTorch, MLflow, GCP Vertex AI, Workflow orchestration tools (i.e. Airflow, Prefect)
• Proficiency with containerization, cloud platforms (AWS, GCP), and CI/CD practices.
• Experience collaborating with cross-functional teams to prioritize, scope, and deploy ML/AI solutions at scale
• Experience helping your teammates grow through mentorship and providing constructive feedback.
• A natural sense of curiosity, and experience with Block's mission of economic empowerment.

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:
$189,000 - $283,600 USD
Zone B:
$179,600 - $269,400 USD
Zone C:
$170,100 - $255,100 USD
Zone D:
$160,700 - $241,100 USD
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 at [email protected] 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.