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.

The Role

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.

What you’ll do

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

What we’re looking for

Required

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

Nice to have

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

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:
$217,800 — $326,800 USD

Zone B:
$207,000 — $310,400 USD

Zone C:
$196,100 — $294,10