Senior Software Engineer, Developer Experience

Block

Remote · Bay Area, CA, USFull-time$217,800–$326,800Posted Oct 23, 2026

About the role

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—$294,100 USD

Zone D:

$185,200—$277,800 USD

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.

Privacy Policy

Responsibilities

  • Lead framework upgrades, language migrations, dependency updates, and other large-scale codebase changes.
  • Design and evolve reliable agentic engineering workflows.
  • Improve developer workflows by addressing build speed, flaky tests, and confusing abstractions.
  • Improve build tooling and CI performance.
  • Create guardrails, tests, and automation to safely land large automated changes.
  • Partner with product engineering teams and measure the impact of developer experience improvements.
  • Set technical direction and mentor engineers on migration strategy, tooling, and codebase health.

Qualifications

  • Typically 7 or more years of experience working in large, complex codebases.
  • Deep experience with application or platform frameworks and managing their evolution.
  • Track record of leading migrations or large refactors from planning through rollout.
  • Ability to navigate unfamiliar code and make sound changes across teams.
  • Understanding of agentic loops, including tool use, context management, verification, and failure handling.
  • Strong communication skills and ability to build trust with teams.
  • Experience with Bazel or similar build systems is a plus.
  • Experience with codemods, AST-based tooling, CI/CD, test infrastructure, developer productivity metrics, or LLM-based coding tools is a plus.

Benefits

  • Remote work
  • Medical insurance
  • Flexible time off
  • Retirement savings plans
  • Modern family planning benefits

Skills mentioned

AI AgentsLarge Language ModelsAutomationCI/CDSoftware TestingUnit TestingIntegration TestingPerformance OptimizationGitSystem Design

About Block

Since we opened our doors in 2009, the world of commerce has evolved immensely, and so has Square. After enabling anyone to take payments and never miss a sale, we saw sellers stymied by disparate, outmoded products and tools that wouldn’t work together. So we expanded into software and started building integrated, omnichannel solutions – to help sellers sell online, manage inventory, offer buy now, pay later functionality through Afterpay, book appointments, engage loyal buyers, and hire and pay staff. Across it all, we’ve embedded financial services tools at the point of sale, so merchants can access a business loan and manage their cash flow in one place. Afterpay furthers our goal to provide omnichannel tools that unlock meaningful value and growth, enabling sellers to capture the next-generation shopper, increase order sizes, and compete at a larger scale. Today, we are a partner to sellers of all sizes – large, enterprise-scale businesses with complex operations, sellers just starting, as well as merchants who began selling with Square and have grown larger over time. As our sellers grow, so do our solutions. There is a massive opportunity in front of us. We’re building a significant, meaningful, and lasting business and helping sellers worldwide do the same. Square is part of Block, Inc. (NYSE: SQ), a global technology company with a focus on financial services.

Software Development1,001-5,000 employeesSan Francisco, CA

H-1B sponsorship history

Historical employer filing data was found for Block. The employer record includes 1,186 historical certified applications. This is employer-level history, not a guarantee that this role currently offers sponsorship.