Senior Machine Learning Modeller at Square

Company Description
It all started with an idea at Block in 2013. Initially built to take the pain out of peer-to-peer payments, Cash App has gone from a simple product with a single purpose to a dynamic app, bringing a better way to send, spend, invest, borrow and save to our millions of monthly active users. With a mission to redefine the world's relationship with money by making it more relatable, available and accessible, at Cash App you'll have the opportunity to make a real-world impact with your career.
Today, Cash App has thousands of employees around the world with a culture geared toward creativity, collaboration and impact. We’ve been a distributed team since day one, and continue to value working across time zones and continents both remotely and in our Cash App offices.
Our offices are great, but many of our roles can be done remotely from the countries where Block operates. We tailor our experience to champion our employees’ creativity and productivity wherever they are.
Job Description
Machine Learning is an integral part of how we design products, operate, and pursue Cash App’s mission to serve the unbanked as well as disrupt traditional financial institutions. Our massive scale and deep trove of transaction data create an endless number of opportunities to use artificial intelligence to better understand our customers and offer new products and experiences that can improve their lives. We are a highly creative group that prefers to solve problems from first principles; we move quickly, make incremental changes, and deploy to production every day.
This role will be embedded on our Risk ML team. In this role you'll build machine learning models that detect fraudulent activity in real time and help keep our customers safe and secure. You will experiment with state-of-the-art algorithms to drive down false positives, collaborate on new product features to drive fraud losses down, use any and every dataset at your disposal (including 3rd party data) to engineer new features for risk models, verify customer documents using OCR, and use biometric and device signals to detect malicious logins and account takeovers.
Technologies we use (and teach):
Python (NumPy, Pandas, sklearn, xgboost, TensorFlow, keras, etc.)MySQL, Snowflake, GCP/AWS and TableauJava
Qualifications
You have:
6+ years experience with applied Machine Learning or Deep LearningA graduate degree in Computer Science, AI, ML, Applied Math, Stats, Physics, or a related technical fieldWorked with Product, Design, and Engineering to prioritize, scope, design, and deploy ML modelsA track record of providing mentorship and technical leadershipAn appreciation for the connection between the software you build and the experience it delivers to customers
Additional Information
We’re working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is a proud equal opportunity employer. We work hard to evaluate all employees and job applicants consistently, based solely on the core competencies required of the role at hand, and without regard to any legally protected class.
We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we’re doing to build a workplace that is fair and square? Check out our I+D page. 
Block, Inc. (NYSE: SQ) is a global technology company with a focus on financial services. Made up of Square, Cash App, Spiral, TIDAL, and TBD, we build tools to help more people access the economy. Square helps sellers run and grow their businesses with its integrated ecosystem of commerce solutions, business software, and banking services. With Cash App, anyone can easily send, spend, or invest their money in stocks or Bitcoin. Spiral (formerly Square Crypto) builds and funds free, open-source Bitcoin projects. Artists use TIDAL to help them succeed as entrepreneurs and connect more deeply with fans. TBD is building an open developer platform to make it easier to access Bitcoin and other blockchain technologies without having to go through an institution.