Design build and operate production ML systems that generate trusted signals for ranking retrieval recommendations propensity/churn/LTV and next-best-action decisioning. Define signal/data contracts own feature and candidate generation through serving experimentation monitoring and feedback loops and evaluate long-term business impact trust fairness and compliance. Partner across product data modeling risk and compliance and apply AI/agents to accelerate engineering and operations.

Block builds simple powerful tools that make progress towards an economy that's truly open to all.
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. Join us.
The Role
As a Staff Applied Machine Learning Engineer focused on Intelligent Data Signals & Systems you will build production ML systems that transform customer behavior product context model outputs and feedback loops into trusted signals used by recommendations ranking risk-aware decisioning growth and customer intelligence systems.
This role centers on customer intelligence and reusable model-derived signal systems: ranking and retrieval recommendations search propensity and churn/LTV next-best-action decisioning experimentation and feedback loops. These systems help product growth fraud and risk teams make better decisions with clear freshness provenance confidence and evaluation guarantees.
The work combines production ML systems with composable signal interfaces that can be consumed by product surfaces decision engines internal tools and verified AI-assisted workflows. The role is flexible across Applied ML Engineering domains while still requiring deep expertise.
You Will

• Build and operate production ML systems that turn customer and product context into trusted signals rankings recommendations and decision capabilities.
• Design production data and signal contracts that define intended use freshness provenance confidence eligibility and calibration for downstream consumers.
• Own ranking retrieval recommendation search propensity and next-best-action systems end to end from feature and candidate generation through serving experimentation monitoring and feedback loops.
• Evaluate customer and business impact beyond short-term conversion including trust fairness access risk compliance long-term engagement and segment-level performance.
• Partner across product growth data platform modeling risk and compliance to translate ambiguous goals into measurable ML system designs.
• Use AI and agents to accelerate development analysis testing documentation and operations while exposing reusable capabilities to product services internal tools and AI-assisted workflows.

You Have

• 12+ years building and operating production software and ML systems for business-critical products.
• Deep expertise in intelligent systems such as ranking/retrieval recommendations search personalization growth and lifecycle ML customer intelligence propensity/churn/LTV next-best-action or model-derived risk signals.
• Strong production ML judgment across feature pipelines model serving experimentation monitoring feedback loops online/offline consistency and reliable signal interfaces.
• Ability to evaluate impact beyond short-term conversion including trust fairness access risk compliance and long-term engagement.
• Experience using AI-assisted engineering tools with appropriate verification testing and review for customer-impacting systems.

Nice to Have

• Experience with semantic retrieval embeddings two-tower models graph features LLM-powered retrieval or decision systems entity resolution or real-time personalization.
• Experience with experimentation online evaluation interleaving counterfactual evaluation multi-objective optimization or long-term holdouts.
• Experience building reusable feature/signal platforms decision services customer intelligence layers model-derived data products or agent-assisted operations.

Technologies We Use and Teach
We do not expect candidates to have used our exact stack. We do expect strong production engineering fundamentals deep domain expertise in intelligent ML systems and judgment about how ML-derived signals should be used safely in customer-impacting products. Examples of technologies and methods include:

• Python Java Kotlin SQL.
• TensorFlow PyTorch XGBoost/LightGBM ranking/retrieval systems embeddings semantic search recommendation frameworks.
• Event streams batch pipelines feature stores model-serving infrastructure workflow orchestration experimentation systems and data warehouses/lakehouses.
• Cloud infrastructure Kubernetes observability tooling coding agents evaluation harnesses and agent-assisted operations tooling.

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 an equal opportunity employer evaluating all employees and job applicants without regard to identity or any legally protected class. We will consider qualified applicants with arrest or conviction records for employment in accordance with state and local laws and "fair chance" ordinances.
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 .
While there is no specific deadline to apply for this role U.S. roles are typically open for an average of 55 days before being filled by a successful candidate. Please refer to the date listed at the top of this job page for when this role was first posted.
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:
$276800 - $415200 USD
Zone B:
$276800 - $415200 USD
Zone C:
$276800 - $415200 USD
Zone D:
$276800 - $415200 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.