Senior Software Engineer, React SDK

About Gusto

At Gusto, we're on a mission to grow the small business economy. We handle the hard stuff—like payroll, health insurance, 401(k) s, and HR—so owners can focus on their craft and customers. With teams in Denver, San Francisco, and New York, we’re proud to support more than 400,000 small businesses across the country, and we’re building a workplace that represents and celebrates the customers we serve.

Learn more about our Total Rewards philosophy.

We’re looking for a Senior Frontend Engineer to join the SDK team within Gusto Embedded. You’ll build the reusable frontend foundation that enables partners to run payroll, manage companies, onboard contractors, and power other critical back‑office workflows directly on top of Gusto’s platform.

In this role, you’ll design and evolve scalable React + Type Script components used across multiple areas of the Gusto platform, shaping how partners integrate and build. You’ll own initiatives from technical design through delivery while working closely with backend and partner-facing teams to expand and mature the SDK.

As the platform grows, you’ll tackle complex business logic, localization, accessibility, and long‑term architectural sustainability—designing abstractions that are powerful, intuitive, and built to scale. This role is ideal for engineers who are excited by platform work, energized by ambiguity, and motivated by building systems that empower other engineers and partners to move faster.

The React SDK team within Gusto Embedded builds the SDK layer that enables partners to power payroll, company management, contractor workflows, and other core back‑office experiences directly on top of Gusto’s platform. We focus on designing reusable interfaces, clear service contracts, and strong developer experience to make integrations reliable and scalable.

As adoption grows, we’re expanding SDK coverage across more areas of the platform while strengthening architectural consistency and long‑term stability. You’ll join a small, high‑ownership team that values thoughtful abstraction, domain understanding, and building tools that empower other engineers and partners to move faster.

• Design and evolve reusable SDK interfaces and components that power payroll, company management, contractor workflows, and other core platform capabilities
• Own technical initiatives from API and abstraction design through production delivery
• Collaborate with backend engineers to define clear, maintainable contracts between platform services and the SDK layer
• Support partner feature development and migrations from legacy integrations to modern SDK interfaces
• Raise SDK quality standards across testing, localization (i18n), accessibility (a11y), and developer experience
• Leverage AI‑assisted development tools strategically to accelerate implementation, improve code quality, and explore new ways of building and evolving SDK capabilities

• 5+ years of professional frontend or platform engineering experience, with strong proficiency in React and advanced Type Script (including API surface and type design)
• Experience building scalable, reusable systems such as SDKs, component libraries, or integration layers
• Strong understanding of frontend–backend integration patterns and experience collaborating on clear service contracts
• Practical experience implementing localization (i18n), accessibility (a11y), and high‑quality testing standards
• Ability to operate effectively in evolving systems and make thoughtful abstraction decisions under ambiguity
• Experience in payroll, HR tech, fintech, or other complex back‑office domains is a strong plus
• Familiarity with AI‑assisted development tools and interest in applying them strategically to improve engineering workflows

Our cash compensation amount for this role is targeted at $140,000–$170,000/year in Denver, $160,000–$185,000/year in Los Angeles, and $170,000–$210,000/year for San Francisco, New York, and Seattle. Final offer amounts are determined by multiple factors including candidate experience and expertise and may vary from the amounts listed above.

Gusto has physical…