Block Senior Software Engineer focused on improving developer experience by leading large-scale codebase changes and enhancing build and test infrastructure. Drive framework and language migrations and develop agentic workflows for AI agents.
Responsibilities
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.
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
Qualification
Experience with codemodsBackground in CI/CDTo find a location’s zone designation$217
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
Preferred
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.
