Intern Ruby Rails Developer Jobs in Boulder, CO (NOW HIRING)

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 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 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. AI experience requirements vary by role and will be assessed during the interview process.
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, 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 Javascript/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, please share with your recruiter.
Our cash compensation amount for this role is targeted at $163,000-$204,000 in Denver & most remote locations, and $197,000-$247,000 for San Francisco & New York. Stock equity is additional. Final offer amounts are determined by multiple factors including candidate experience and expertise and may vary from the amounts listed above.
Gusto has physical office spaces in Denver, San Francisco, and New York City. Employees who are based in those locations will be expected to work from the office on designated days approximately 2-3 days per week (or more depending on role). The same office expectations apply to all Symmetry roles, Gusto's subsidiary, whose physical office is in Scottsdale.
Note: The San Francisco office expectations encompass both the San Francisco and San Jose metro areas.
When approved to work from a location other than a Gusto office, a secure, reliable, and consistent internet connection is required. This includes non-office days for hybrid employees.
Our customers come from all walks of life and so do we. We hire great people from a wide variety of backgrounds, not just because it's the right thing to do, but because it makes our company stronger. If you share our values and our enthusiasm for small businesses, you will find a home at Gusto.
Gusto is proud to be an equal opportunity employer. We do not discriminate in hiring or any employment decision based on race, color, religion, national origin, age, sex (including pregnancy, childbirth, or related medical conditions), marital status, ancestry, physical or mental disability, genetic information, veteran status, gender identity or expression, sexual orientation, or other applicable legally protected characteristic. Gusto considers qualified applicants with criminal histories, consistent with applicable federal, state and local law. Gusto is also committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. We want to see our candidates perform to the best of their ability. If you require a medical or religious accommodation at any time throughout your candidate journey, please fill out this form and a member of our team will get in touch with you.
Gusto takes security and protection of your personal information very seriously. Please review our Fraudulent Activity Disclaimer.
Personal information collected and processed as part of your Gusto application will be subject to Gusto's Applicant Privacy Notice.