Staff Software Engineer, PEO Benefits

About Gusto

At Gusto, we're on a mission to grow the small business economy. We handle the hard stuff — payroll, health insurance, 401(k)s, and HR — so owners can focus on their craft and their customers. With teams in Denver, San Francisco, and New York, we support more than 500,000 small businesses nationwide.

AI is a fundamental part of how work gets done at Gusto. We expect all team members to actively engage with AI tools relevant to their role and grow their fluency as the technology evolves.

About the Role

We're looking for seasoned full-stack software engineers to join Gusto’s PEO Benefits team.

Gusto is standing up a Professional Employer Organization (PEO) — one of the biggest new bets in the company — and Benefits is the anchor of the offering. At the core is a national Master Health Plan that can unlock ~20–25% lower healthcare costs for small businesses through pooled purchasing power. You'd be joining the engineering team building the systems that make that real.

As a Staff Software Engineer, you'll operate across the full product lifecycle: shaping features from early spec and design through to launch and long-term iteration. That means writing clean frontend code, designing and building reliable backend APIs, influencing product direction, and taking ownership of what happens after a feature ships.

Responsibilities

• Design, build, and test the Gusto PEO Benefits experience - the benefits shopping and plan-recommendation flows, carrier integrations, MCP tools, and agents that automate operational and customer support processes
• Mentor other engineers to help solve complex technical problems at scale
• Help scale one of the largest Ruby/Rails and Javascript/React applications in the world
• Collaborate with Product Management, Data, Design, and Platform Engineering teams to understand customer pain points, prototype, iterate, and launch daily
• Build products that customers love

Qualifications

• Typically 8+ years of software development experience
• Experience owning multi-quarter projects that solve complex engineering problems and make measurable customer impact at scale
• Experience driving large, cross-functional projects end-to-end through ambiguity
• Experience leveraging AI tools or systems to accelerate development, improve testing, and deliver new product capabilities
• Curiosity and experimentation with emerging AI frameworks, applying and sharing best practices to evaluate and scale AI use safely across teams
• Ability to mentor engineers to maximize their performance and impact
• Ability to build well-structured, maintainable, well-documented code
• Ability to effectively communicate across engineering teams and with business stakeholders

Preferred Qualifications

• 3+ years of experience with PEO, with direct experience building PEO flows in a high-growth environment
• Experience in, or interest working in, Ruby on Rails
• Appreciation for a collaborative, test-driven environment

Additional Requirements

• Travel to Gusto's office for onboarding is required for this position
• Hybrid office expectations: 2-3 days per week in Denver, San Francisco, or New York City