Staff Software Engineer

Gusto is on a mission to grow the small business economy, handling payroll, health insurance, 401(k)s, and HR for over 500,000 small businesses nationwide. With teams in Denver, San Francisco, and New York, Gusto is building a workplace that reflects the people it serves. All full-time employees receive competitive base pay, benefits, and equity (RSUs).

As a Staff Software Engineer on the Gusto Pro Integrations team, you will build and own integrations between Gusto and third-party tools used by accounting firms. The team maintains a growing portfolio of integrations, including Bookkeeping integrations, and expects to expand what integrations mean for Gusto Pro. You will work hands-on across the stack (Ruby on Rails, Sidekiq), evaluating both traditional API integrations and emerging AI agent protocols like MCP (Model Context Protocol), while partnering with Product, Design, and Data Science.

• Own and extend existing third-party integrations and build new ones as the portfolio grows.
• Design and build reliable backend services (Ruby on Rails, Sidekiq) that sync data between Gusto and partner platforms.
• Evaluate and help build new integration patterns, including AI agent protocols like MCP.
• Help define the technical approach and roadmap as the Integrations domain grows.
• Partner with Product, Design, and Data Science to validate accountant workflows.
• Participate in code review and set the technical bar for the team.
• Mentor other engineers as the team scales.

• 8+ years of professional software development experience.
• Experience owning multi-quarter projects end-to-end.
• Strong platform/application engineering background: services, APIs, third-party integrations, data flows, observability.
• Comfortable operating in an ambiguous, early-stage domain.
• Ruby on Rails experience strongly preferred; OAuth and third-party API integrations a plus.
• Familiarity with AI agent protocols (e.g., MCP) or agentic integration patterns is a plus.
• Excellent communication skills.
• AI-native mindset with AI tools embedded in daily workflow.

Cash compensation is targeted at $163,000–$204,000 in Denver, and $197,000–$247,000 for San Francisco, Seattle & New York. Stock equity is additional. Final offers may vary based on experience and expertise.

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