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.
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:
$276,800 - $415,200 USD
Zone B:
$276,800 - $415,200 USD
Zone C:
$276,800 - $415,200 USD
Zone D:
$276,800 - $415,200 USD
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 at [email protected] 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.