Senior Machine Engineer

Website Cash App

Redefine the world's relationship with money.

About the job
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 ecosystem, developing unique financial products, including Afterpay/Clearpay, to provide a better way to send, spend, invest, borrow and save to our 47 million monthly active customers. We want to redefine the world’s relationship with money to make it more relatable, instantly available, and universally accessible.

Today, Cash App has thousands of employees working globally across office and remote locations, with a culture geared toward innovation, collaboration and impact. We’ve been a distributed team since day one, and many of our roles can be done remotely from the countries where Cash App operates. No matter the location, we tailor our experience to ensure our employees are creative, productive, and happy.

Check out our locations, benefits, and more at

Job Description

Marketplace under Cash App provides different payment products such as BNPL (Buy Now, Pay Later) or pay monthly to customers. The Fraud Risk team is responsible for building scalable systems that power our modelers and decision scientists to develop & deploy ML-based strategies to battle fraudsters to ensure the health of the business. In addition, we build end-to-end customer experience for risk assessments.

As a member of the team, you will design, build and launch fraud risk products and features. We build our services over Cash App’s ever-evolving infrastructure, and as a senior engineer on the team, you will embrace these changes and scale our tech stack to enable future evolvability. This is an exciting opportunity to make a direct, tangible impact on our product and work on projects that are pivotal to the business’s success.

You Will

Develop highly scalable systems, algorithms, and tools on one platform to support machine learning solutions
Develop, integrate, and optimize end-to-end ML pipeline
Demonstrate rigor in high code quality, good test coverage, and other engineering best practices
Collaborate with product, analysts, and modelers on planning and implementing frictionless user experiences
Have autonomy to research and achieve outcomes with support when you need it
Contribute to the growth of our development capabilities through leading, mentoring, and supporting fellow engineers
Help build the next generation of machine learning products at CashApp
Work in any AU Cash App office location, or work remotely in Australia.



You Have

7+ years of backend software development experience in building and maintaining applications in any mainstream language such as: Java, JavaScript, Python, Kotlin, Ruby, Go, Swift, C++
Enthusiastic about solving business problems with technology and can take ownership of an end-to-end solution
Passionate about continuously learning new technologies, frameworks, and services
Possess an execution mindset and the ability to deliver with cross-functional teams that are globally distributed
Serious about testing and have experience with automated testing frameworks
Passion for Cash App’s mission of economic empowerment
Experience of ML model-related experience is a bonus
Experience with common technologies, for example, Kafka, Redis, Cassandra is a bonus
A keen interest in advancing Cash App’s vision of building for economic empowerment


Tools we use and teach

Python, Java, Kotlin
Onnx/PyTorch, LightGBM/XGBoost
Kubernetes, AWS
Datadog, SumoLogic
Hibernate, MySQL, Cassandra DB, DynamoDB
HTTP, JSON, gRPC, Protocol Buffers
Kafka, event-driven microservice architecture


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.

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