Staff Machine Learning Engineer, Underwriting and Credit
Block, Inc. is a technology company building tools for economic empowerment, operating a portfolio of financial brands including Square, Cash App, Afterpay, TIDAL, Bitkey, and Proto. It serves sellers, consumers, artists, and bitcoin users through payments, banking, buy-now-pay-later, music streaming, and bitcoin self-custody and mining products.
About Block, Inc.
Block, Inc. builds technology aimed at increasing access to the global economy. Its brands each unlock different aspects of the economy: Square makes commerce and financial services accessible to sellers; Cash App is an easy way to spend, send, and store money; Afterpay (Clearpay in the UK) helps customers manage spending over time; TIDAL is a music platform empowering artists as entrepreneurs; Bitkey is a self-custody bitcoin wallet; and Proto builds open, accessible bitcoin mining hardware and services. Block has been a long-time advocate for bitcoin, integrating bitcoin buying/selling and Lightning Network payments into Cash App and Square, funding open-source bitcoin infrastructure through Spiral (including the Lightning Development Kit), and engaging in bitcoin policy advocacy through groups like COPA, the Digital Energy Council, the Crypto Council for Innovation, and the Texas Blockchain Council. The company also runs a significant open source program (contributing to projects like Goose, an on-machine AI developer agent, OkHttp, Retrofit, gRPC, Envoy, and MySQL) and an AI research effort, including co-founding the Agentic AI Foundation with Anthropic and OpenAI. Block serves individual consumers, small and medium-sized businesses/merchants, artists, and developers.
Skills
About the Role
You will be a senior contributor on the Credit Modeling team, building and evolving ML systems behind underwriting and credit products across the full modeling lifecycle. The role focuses on credit decisioning, experimentation, production model operations, and AI-assisted engineering workflows. It is fully remote for candidates based in the US or Canada.
Requirements
- Bachelor's degree in a quantitative field such as Mathematics, Statistics, Physics, or Computer Science; advanced degrees welcome.
- 10+ years applying AI, machine learning, or statistical modeling in decisioning contexts such as credit, risk, fraud, recommendations, or similar domains.
- Experience with probabilistic models and decision systems, including calibration, score transformations, and model-output interpretation.
- Strong experimentation skills, including holdouts, lift measurement, and evaluation beyond aggregate metrics.
- Experience with production model monitoring, degradation detection, and retraining strategies.
- Proficiency with AI-native development workflows, LLMs, agentic coding tools, and AI-assisted automation.
- Experience explaining modeling concepts, results, and limitations to senior stakeholders and cross-functional partners.
- Experience working across disciplines in environments with meaningful constraints.
Responsibilities
- Build, evaluate, and maintain underwriting and decisioning models across Cash App Borrow and Afterpay.
- Design and evolve credit decision frameworks, modeling automation, and policy logic that manage credit exposure over time.
- Design and run experiments to evaluate model performance, approval rates, loss, and credit policy decisions.
- Develop understanding of borrower behavior, repayment dynamics, and portfolio structure to inform model design and decision logic.
- Explain model behavior, tradeoffs, and uncertainty to senior technical and business leaders.
- Work across problem formulation, feature engineering, training, calibration, deployment, monitoring, and iteration in production.
- Build agentic engineering workflows that accelerate development, testing, and documentation.
- Collaborate with Product, Engineering, Legal, Compliance, and Operations.
- Share modeling context and approaches across teams.
- Shape AI developer tooling adoption through review practices, quality standards, and governance patterns.
Benefits
- Remote work
- Medical insurance
- Flexible time off
- Retirement savings plans
- Modern family planning
