Staff Machine Learning Engineer, Predictive Systems

Block•San Francisco, CA

About The Position

The Role As a Staff Machine Learning Engineer on the Predictive Systems team, you will drive the technical strategy for ML and decisioning systems that address risk, fraud, and abuse across Block. Acting as a technical domain owner for Cash App, Square, and Afterpay, you will shape how AI solutions are architected, integrated, and operationalized. Your leadership ensures that risk management functions as an enabler for product velocity, allowing teams to deploy features rapidly while maintaining a trusted ecosystem. You are accountable for the production lifecycle of these systems, orchestrating the convergence of data, features, models, and controls into scalable defenses. Operating at the ecosystem level, you will define durable abstractions and decisioning patterns that standardize risk strategies across diverse domains. You will also influence the roadmap of Block's core ML infrastructure, ensuring the platform evolves to meet the requirements of complex, high-volume decisioning workloads.

Requirements

Extensive experience designing and leading large-scale ML systems with broad organizational impact.
A proven ability to set technical vision and drive alignment across multiple teams and disciplines.
Deep understanding of ML systems, data platforms, and real-time decisioning at scale.
Strong judgment in navigating complex tradeoffs involving risk, trust, and product velocity.
A history of mentoring senior engineers and developing future technical leaders.
A systems-level mindset and a bias toward durable, high-leverage solutions.

Responsibilities

Act as a technical lead across multiple Risk ML engineering teams, setting direction for how ML and AI solutions are applied to fraud, abuse, and risk decisioning.
Design and evolve real-time and batch ML systems that leverage Block's core ML platforms to deliver scalable risk solutions.
Drive architectural decisions around feature usage, contextual signals, and ML-driven controls in partnership with modeling, product, and platform teams.
Translate ambiguous risk problems into clear technical strategies and execution plans.
Lead cross-team efforts to integrate new data sources, signals, and event hooks into production risk systems.
Establish standards for data quality, observability, and correctness for ML inputs and decisions.
Provide technical leadership during emerging threat and SEV scenarios, guiding rapid mitigation while preserving long-term system health.
Influence ML and AI engineering practices across Risk, improving consistency, reliability, and velocity.

Benefits

Healthcare coverage (Medical, Vision and Dental insurance)
Health Savings Account and Flexible Spending Account
Retirement Plans including company match
Employee Stock Purchase Program
Wellness programs, including access to mental health, 1:1 financial planners, and a monthly wellness allowance
Paid parental and caregiving leave
Paid time off (including 12 paid holidays)
Paid sick leave (1 hour per 26 hours worked (max 80 hours per calendar year to the extent legally permissible) for non-exempt employees and covered by our Flexible Time Off policy for exempt employees)
Learning and Development resources
Paid Life insurance, AD&D, and disability benefits
This role is also eligible to participate in Block's equity plan subject to the terms of the applicable plans and policies, and may be eligible for a sign-on bonus.