Senior Software Engineer, Developer Experience

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.

About the role

More and more of our engineering work now runs through autonomous agents, and those agents can only be as effective as the tools, context, and codebase around them. As a Developer Experience Engineer, you'll build the tooling and agent workflows that let humans and agents change our largest monorepos quickly and safely.

You'll own the interfaces engineers use to observe, steer, and give context to the agents working on our code. You'll also build the guardrails that keep complexity in check as those agents take on bigger changes. Large-scale work like framework upgrades, language migrations, and dependency health is still part of the job, but you'll do it by building and steering agents rather than making the changes by hand. This is a high-leverage role. Every improvement you ship multiplies across the whole engineering organization.

What you’ll do

• Build and ship the tools engineers and their agents use every day, such as CLIs, desktop integrations, and interfaces for observing, unblocking, and steering autonomous agents, and own their adoption, distribution, and support
• Design and evolve agentic loops (the plan, act, verify, and iterate cycles) and the harnesses, skills, and context that let agents do real engineering work reliably
• Build agent workflows that drive large-scale changes across the codebase, including framework upgrades, language migrations, and dependency updates, with minimal disruption to product teams
• Build the guardrails, tests, and automation that make large, agent-authored changes safe to land, and track the leading indicators of growing complexity
• Find friction in the development workflow for both humans and agents, and fix the root causes
• Partner with builders inside and outside of engineering to understand their pain points, and measure the adoption and impact of what you ship
• Set technical direction and mentor other engineers on agent design, tooling, and codebase health

What we’re looking for

We care more about what you've done than about which specific technologies you used to do it.

Required

• Shipping developer tooling at scale: You've shipped tools that engineers use daily, such as CLIs, desktop integrations, configuration management, or internal platforms. You understand what it takes to drive adoption, debug problems, and support users.
• Scaling work with agents: You've built agent workflows that finished work that would normally take a team weeks. Examples include generating codebase summaries or world models, writing skills and loops, or orchestrating a team of semi-deterministic agents. You have a deep understanding of agentic loops (tool use, context management, verification, failure handling) and are eager to keep evolving them as the field changes.
• Evolving frameworks and large codebases: You have deep experience with application or platform frameworks, including upgrading them and managing their evolution over time. You also have a track record of leading migrations or large refactors from planning through rollout.
• Significant experience (typically 10+ years for Staff, 7+ for Senior) working in large, complex codebases
• Strong communication skills and the ability to build trust with teams by owning the outcomes of your work

Nice to have

• Experience with harness engineering or context engineering
• Experience with agent observability, for example through OpenTelemetry
• Experience distributing internal tools (versioning, release channels, auto-update) and measuring adoption with telemetry or surveys
• Background in developer productivity metrics, test infrastructure, or CI/CD
• A passion for intuitive user experience and good taste in elegant solutions
• Open source contributions to developer tooling or agent frameworks

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. 

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.

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