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.

Our engineers are only as effective as the tools, codebase, and workflows around them. As a Developer Experience Engineer, you’ll make our large, evolving codebase easier to build, change, and reason about, for both human developers and AI agents.

You will be responsible for the developer experience in our largest monorepos: building tools for and driving framework and language migrations, keeping dependencies healthy, improving build and test infrastructure, and shaping how agentic workflows operate in our development process. This is a high-leverage role. Every improvement you ship multiplies across the whole engineering organization.

• →Lead and execute large-scale changes across the codebase, including framework upgrades, language migrations, and dependency updates, with minimal disruption to product teams
• →Design and evolve agentic loops: the plan, act, verify, and iterate cycles that let AI agents do real engineering work safely and reliably
• →Identify friction in the developer workflow (slow builds, flaky tests, confusing abstractions) and fix the root causes
• →Improve build tooling and CI performance, including work with Bazel or a comparable build system
• →Build the guardrails, tests, and automation that make large, automated changes safe to land
• →Partner with product engineering teams to understand their pain points and measure the impact of your work
• →Set technical direction and mentor other engineers on migration strategy, tooling, and codebase health

• Significant experience (typically 7+ years for Senior, 10+ for Staff) working in large, complex codebases
• Deep experience with application or platform frameworks, including upgrading them and managing their evolution over time
• Track record of leading migrations or large refactors, from planning through rollout
• Comfort navigating unfamiliar code quickly and making sound changes across many teams’ areas
• A solid understanding of agentic loops (tool use, context management, verification, failure handling) and a genuine willingness to keep investing in and evolving them as the field changes
• Strong communication skills and the ability to build trust with teams whose code you’re changing

• Hands-on experience with Bazel or similar build systems (Buck, Pants, Nx, Gradle, etc.)
• Experience with codemods, AST-based tooling, or automated refactoring at scale
• Background in CI/CD, test infrastructure, or developer productivity metrics
• Experience building or integrating LLM-based coding tools into engineering workflows
• Open source contributions to build tools, frameworks, or developer tooling

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.

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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