Staff Backend Engineer - Payroll Platform & APIs

At Gusto, we're on a mission to grow the small business economy by simplifying payroll, health insurance, 401(k)s, and HR for more than 500,000 small businesses nationwide.

We are hiring a Staff Software Engineer to join Gusto’s Payroll Platform team, where you’ll build backend product infrastructure that powers payroll experiences across Gusto. This is a fully backend role focused on designing and evolving internal APIs and services used by other product teams to deliver accurate, compliant, and scalable payroll. You’ll own complex technical problems end-to-end, partner closely with other engineering teams, and help raise the bar on how payroll capabilities are built and consumed across the company.

About the Team

The Payroll Platform team builds the foundational services that make payroll possible at Gusto. Our customers are internal product teams building payroll, time, contractor, and accountant experiences, as well as external partners through Gusto Embedded Payroll. We focus on creating reliable, performant, and well-designed APIs that abstract away payroll complexity and enable teams to move faster with confidence. Our work sits at the intersection of backend product engineering, developer experience, and large-scale systems in a highly regulated domain.

Key Responsibilities

• Backend Architecture & APIs: Design, build, and maintain backend services and APIs that support core payroll workflows and are consumed by multiple Gusto engineering teams.
• Domain Ownership: Own a primary domain within the Payroll Platform, taking responsibility for system health, correctness, scalability, and long-term evolution.
• Technical Partnership: Act as a technical partner to internal engineering teams, collaborating closely to guide platform adoption and co-design solutions that scale across use cases.
• System Design & Documentation: Author and drive architecture and design documents, establishing technical direction while balancing near-term delivery with long-term platform goals.
• Scalability & Performance: Improve system performance, reliability, and observability as payroll processing scales for hundreds of thousands of businesses.
• Cross-Functional Collaboration: Partner with Product, Design, Data, Compliance, and Operations to deliver compliant, high-impact solutions.
• AI Tool Integration: Routinely leverage AI-assisted development tools (LLMs, Claude Code, Cursor) to accelerate development, improve code quality and documentation, and foster effective adoption across the team.

Requirements

Experience & Education

• 8+ years of professional software engineering experience, with a heavy focus on backend development.
• Proven track record of building and scaling internal platforms, shared services, or foundational APIs supporting multiple product teams.
• Ability to work independently on ambiguous problems from business requirement analysis to delivery and iteration.

Technical Skills

• Strong proficiency in one or more backend programming languages (experience with Ruby is strongly preferred but not required).
• Deep system design expertise, including performance optimization, scalability, and reliability in production systems.
• Active practice using AI-assisted development tools (LLMs, Claude Code, Cursor) in daily engineering workflows and guiding teams on responsible adoption.

Soft Skills & Mindset

• Strong collaborative mindset with experience acting as a technical partner in product-focused engineering organizations.
• Excellent communication skills to interface effectively across engineering teams and business stakeholders.

Benefits & Total Rewards

• Equity: Competitive stock grants (RSUs) included with all full-time offers.
• Healthcare & Care: Comprehensive health, dental, and vision insurance plus mental health counseling.
• Financial & Retirement: 401(k) plan and flexible financial benefits.
• Flexibility & PTO: Generous paid time off, parental support, and flexible hybrid/remote arrangements.