Senior Software Engineer, Developer Experience

Block•Bay Area, CA, United States of America, CA

4h•$185,200 - $326,800

About The Position

Block is hiring a Developer Experience Engineer to improve the tools, codebase, and workflows used by engineers and AI agents. The role focuses on Block’s largest monorepos, making them easier to build, change, and understand. This high-leverage position involves framework and language migrations, dependency health, build and test infrastructure, and the design of agentic workflows in engineering.

Requirements

Significant experience working in large, complex codebases; typically 7+ years for Senior and 10+ years for Staff.
Deep experience with application or platform frameworks, including upgrading them and managing their evolution.
Track record of leading migrations or large refactors from planning through rollout.
Ability to navigate unfamiliar code quickly and make sound changes across many teams’ areas.
Understanding of agentic loops, including tool use, context management, verification, and failure handling, and willingness to continue investing in and evolving them.
Strong communication skills and ability to build trust with teams whose code is being changed.

Nice To Haves

Hands-on experience with Bazel or similar build systems, such as Buck, Pants, Nx, or Gradle.
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.

Responsibilities

Lead and execute large-scale codebase changes, including framework upgrades, language migrations, and dependency updates, while minimizing disruption to product teams.
Design and evolve agentic loops that enable AI agents to perform engineering work safely and reliably.
Identify and address root causes of developer workflow friction, such as slow builds, flaky tests, and confusing abstractions.
Improve build tooling and CI performance, including work with Bazel or a comparable build system.
Build guardrails, tests, and automation to make large automated changes safe to land.
Partner with product engineering teams to understand pain points and measure the impact of improvements.
Set technical direction and mentor engineers on migration strategy, tooling, and codebase health.