Senior Staff Machine Learning Engineer, AI Engineering Tools

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

The AI Engineering Tools team accelerates engineering velocity by integrating AI throughout the software development lifecycle. We're redefining how engineers build software by making development faster, more creative, and more reliable through intelligent, AI-driven tooling. Our mission is to help every engineer at Block leverage AI effectively, safely, and efficiently.

We're looking for an experienced software engineer to help advance the next generation of AI-assisted development at Block. In this role, you'll work across AI infrastructure and developer tooling to build and optimize coding agents that empower engineers company-wide. You'll collaborate with platform and product teams to refine user experiences, introduce new capabilities, and improve the performance of coding agents.

This is a unique opportunity to shape how AI transforms engineering itself. You'll work on projects that continuously improve AI coding agents across all Block repositories, enhancing their ability to understand context, complete tasks, and assist with real-world development workflows.

You Will

• Design and build AI-driven developer tools that integrate seamlessly into the software development lifecycle (e.g., intelligent code assistance, inline reviews, or automated refactoring systems).
• Partner with vendors and internal teams to evaluate, integrate, and optimize AI engineering tools.
• Collaborate with engineering leaders across Block to identify opportunities for AI integration that improve developer velocity and code quality.
• Mentor engineers, contribute to design and code reviews, and help establish best practices for building reliable AI systems at scale.

You Have

• 12+ years of experience building and shipping production systems.
• Strong software engineering background, with fluency in designing scalable backend systems.
• Deep understanding of LLMs, prompt engineering, and applied ML workflows from experimentation and evaluation to deployment and monitoring.
• Experience integrating third-party AI models (e.g., OpenAI, Anthropic, or custom fine-tuned models) into real-world tools or services.
• A pragmatic approach to experimentation and iteration, balancing innovation with reliability and security.
• Strong communication and cross-functional collaboration skills, especially with engineers, product managers, and leadership.
• Familiarity with developer ecosystems, IDEs, or productivity platforms is a plus (e.g., VS Code, Cursor, GitHub Copilot, etc.).

You’ll help define how thousands of engineers across Block leverage AI to write better code, faster. Your work will shape the foundation for the next generation of developer productivity — one where AI is a trusted collaborator that elevates creativity, accelerates delivery, and improves software quality at scale.

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.