Software Engineer, PEO

Staff Software Engineer, PEO Benefits

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 and are building a workplace that reflects the people we serve.

All full-time employees receive competitive base pay, benefits, and equity (RSUs) — because everyone who helps build Gusto should share in its success. Offer amounts are determined by role, level, and location. Learn more about our Total Rewards philosophy.

AI is a fundamental part of how work gets done  expect all team members to actively engage with AI tools relevant to their role and grow their fluency as the technology evolves. AI experience requirements vary by role and will be assessed during the interview process.

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, something most PEOs can't pull off in year one. You'd be joining the engineering team building the systems that make that real.

This is rare greenfield scope inside a company with real scale and real customers. You get to make foundational architectural decisions, not maintain someone else's.

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.

If you're drawn to work that combines technical craft with real-world impact — helping power the livelihoods of millions using Gusto products — join us!

Here's what you'll do day-to-day:

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

Here's what we're looking for:

• Successful applicants typically have 8+ years of software development experience
• PEO Expertise (Preferred): 3+ years of experience with PEO, with direct experience building PEO flows in a high-growth environment.
• 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 — scoping, sequencing, and unblocking without needing the problem pre-broken-down; aligning multiple stakeholders and working with multiple teams
• 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

Others:

• Experience in, or interest working in, Ruby on Rails
• Appreciation for a collaborative, test-driven environment
• Ability to build well-structured, maintainable, well-documented code
• Ability to effectively communicate across engineering teams and with business stakeholders

Please note that travel to Gusto's office for onboarding is required for this position. If you have any questions regarding this requirement,…