Principal Software Engineer, State Tax Registration & Closure

About the Role

We're hiring a seasoned engineer to help stand up a newly formed team dedicated to State Tax Registration & Closure — the systems that get Gusto customers registered with state tax agencies when they start operating in a new state, and cleanly closed out when they stop. As a Principal Software Engineer, you'll shape this team's technical direction from the ground up: defining the architecture, evolving legacy registration and closure workflows toward a more scalable and automated future, and partnering closely with Compliance and Operations to keep customers in good standing across every state they touch.

This role starts focused: get State Tax Registration & Closure onto solid technical footing in the first year. From there, we expect your scope to grow — taking on broader technical influence across Company Group as you prove out the team's foundation. If you're excited about building elegant software with far-reaching effects in the modern economy, and about growing your impact alongside a newly forming team, we'd love for you to join us!

About the Team

Company Group builds the products that help small businesses become — and stay — legitimate, compliant companies, tackling the "back office" work that has everything to do with keeping a business in good standing. That spans forming a legal entity, registering and filing with state and local agencies, business insurance, and the ongoing compliance obligations that come with operating across multiple states.

Our Products

Business Compliance & Entity Management: Owns the products that help customers form and maintain their legal entity — filings, registered agent services, annual reports, and the ongoing paperwork that keeps a business in good legal standing.

Start Your Business: Helps first-time founders go from idea to registered, compliant business — entity formation, EIN setup, and the guidance new business owners need to get started with confidence.

Solo: Builds a back-office experience tailored to solo entrepreneurs and S-corp owners, simplifying the compliance and tax decisions that typically require an accountant.

Business Insurance: Owns the end-to-end business insurance experience, helping customers find and maintain the coverage (workers' comp, general liability, PEO) their state and industry require.

State Tax Registration & Closure (what you'll build): The future of how Gusto customers register for state payroll taxes as they expand into new states, and how those state tax accounts get cleanly closed out when a customer stops operating there. Multi-state registration and closure today is a maze of shifting agency requirements, inconsistent (and often paper-based) processes, and manual workarounds — the job here is to build AI-first, agentic automation that takes action on a customer's behalf (filling out and filing registration paperwork, following up with agencies, closing accounts) instead of routing everything through manual review, giving customers and Gusto's Compliance and Operations teams confidence at scale.

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

• Function as the founding Technical Lead for State Tax Registration & Closure, standing up the team's technical foundation and setting technical direction from day one.
• Design, build, and test the systems that register and close out Gusto customers' state tax accounts as they start and stop operating across all 50 states.
• Grow your remit over your first year — from building and scaling State Tax Registration & Closure to taking on broader technical influence across Company Group.
• Help scale one of the largest Ruby on Rails and TypeScript/React applications in the world.
• Collaborate on complex and ambiguous problems in partnership with Engineering, Product Management, Design, Data Science, Compliance, Operations, and other cross-functional teams.
• Mentor and support fellow engineers in creating holistic, scalable solutions.
• Drive the product development process from concept to launch, delivering products that make company compliance simple and easy.
• Build services, tools, and APIs that make Gusto's engineering, compliance, and operations teams more effective.
• Work in a highly supportive environment that fosters collaboration, productivity, and innovation.
• Stay current with advancements in AI and Machine Learning, applying this knowledge to our projects.

Here's what we're looking for:

• 15+ years of experience (successful applicants typically meet or exceed this).
• Ability to build maintainable, structured, and well-documented code.
• Strong knowledge of data structures, data modeling, and system design.
• Experience working across 3+ teams, influencing both product and team direction.
• Experience developing platform products that are relied on company-wide.
• Proven background in engineering, designing, building, and supporting large-scale production systems.
• Ability to bring clarity and simplicity to complex problems, communicate technical complexity, and facilitate informed trade-offs with major stakeholders.
• Experience operationalizing and scaling large, interconnected production systems.
• Enthusiasm for a collaborative, test-driven environment.
• Experience in complex, highly regulated domains (e.g., HR, Payroll, Taxes, Compliance), ideally including direct integration with government agencies and their idiosyncratic systems.
• Experience using AI tools to build, test, and iterate on products quickly.
• Understanding of how to evaluate AI-driven outputs using clear success criteria.
• Experience building agentic systems that take action and/or automate toil, and a commitment to staying current on emerging backend technologies and AI frameworks and patterns.
• Willingness to contribute to shared tools or templates that enhance the speed and safety of AI experimentation.

Our cash compensation for this role is targeted at $239,000–$264,000 per year in Denver and most remote locations, and $280,000–$309,000 per year in San Francisco, Seattle, and New York. Stock equity is offered in addition. Final offer amounts are determined by multiple factors, including candidate experience and expertise, and may vary from the ranges listed above.