Staff Machine Learning Engineer (Modeling), Support

Block is one company built from many blocks, all united by the same purpose of economic empowerment. The blocks that form our foundational teams — People, Finance, Counsel, Hardware, Information Security, Platform Infrastructure Engineering, and more — provide support and guidance at the corporate level. They work across business groups and around the globe, spanning time zones and disciplines to develop inclusive People policies, forecast finances, give legal counsel, safeguard systems, nurture new initiatives, and more. Every challenge creates possibilities, and we need different perspectives to see them all. Bring yours to Block.

The Role

Block's Support ML Modeling team is a central driver of innovation in customer support experiences across our entire ecosystem—including Cash App, Square, and other business units. We are dedicated to advancing the state of intelligent, automated support through machine learning and generative AI. From customer-facing chatbots to smart internal tools for agents, our team builds high-impact, scalable systems that improve support quality, efficiency, and accessibility.

We're building the future of support at Block: one powered by AI, voice interfaces, and smart automation. We're looking for candidates with a passion for intelligent systems, practical ML experience, and a desire to build product-driven solutions. Our ideal candidate is a leader in the field, with a proven track record of building ML systems that can accelerate our ability to scale our conversational AI initiatives.

You Will

• Lead the end-to-end delivery of multiple ML initiatives, from planning and design through rollout, documentation, and long-term maintenance
• Partner strategically with risk, product, engineering, design, and operations leaders to define and drive long term ML roadmaps, informed by domain expertise and industry trends
• Guide the team’s direction, identifying new ML/AI opportunities and advising leadership on strategic tradeoffs and opportunities
• Drive R&D efforts exploring next-generation chatbot architectures using LLMs, RAG, fine-tuning, and real-time inference
• Design, deploy, and maintain ML models powering conversational agents including support chatbots across Cash App, Square, and other Block products
• Develop ML-powered tools and real time recommendation systems that enhance support agent effectiveness and customer outcomes
• Act as the technical representative for your team’s systems and programs, clearly communicating work and results to stakeholders, cross-functional partners, and external audiences

You Have

• 10+ years of experience in machine learning, applied AI, or product ML roles, with deep technical expertise
• Demonstrated leadership capabilities, with the ability to influence and align cross-functional teams while directly shaping the work of peers through communication, context sharing, and technical guidance
• A track record of delivering organizational wide impact, shaping systems, frameworks, or initiatives that raise the bar across multiple teams or functions
• Proven ability to ship end to end ML features from problem framing through deployment and long-term maintenance
• Demonstrated experience with language models, dialog systems, or generative AI in production
• Strong foundation in NLP, deep learning, or ML infrastructure best practices.
• Excellent communication skills, with the ability to represent the team’s work to leadership and stakeholders
• Enthusiasm for R&D and pushing the boundaries of applied AI to transform conversational systems

Technologies We Use and Teach

• Languages & Frameworks: Python, PyTorch, TensorFlow, JAX
• Model Types: Transformer, LLMs, Retrieval-Augmented Generation (RAG), classifiers, ranking models
• Tooling: ML pipelines, batch/real-time inference, experiment tracking tools

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 lea