Staff Software Engineer, Gusto Pro

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: As a Staff Software Engineer on Gusto Pro Integrations, you'll build and own integrations between Gusto and the third-party tools accounting firms already use to run their practice. The team maintains a growing portfolio of integrations today (including our Bookkeeping integrations), and we expect that portfolio to keep expanding as the team grows what "integrations" means for Gusto Pro. You'll work hands-on across the stack (Ruby on Rails, Sidekiq), including evaluating both traditional API integrations and emerging AI agent protocols like MCP (Model Context Protocol), while partnering closely with Product, Design, and Data Science to make sure every integration fits naturally into how accountants actually work. This is a high-ownership role on a small, growing team: the Integrations roadmap ahead isn't fully defined yet, and you'll have real input into what gets built next. About the Team: The Gusto Pro Integrations team builds and maintains integrations between Gusto and the third-party software used by accounting firms — including our existing Bookkeeping integrations, with more added over time. We expect the set of integrations we own to keep growing, across the various tools and platforms accountants already rely on. We work closely with Gusto Pro's other teams to deliver a seamless experience for accounting professionals. Here’s what you’ll do day-to-day: Own and extend Gusto's existing third-party integrations and help build out 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 — as we expand beyond traditional API integrations Help define the technical approach and roadmap as the Integrations domain grows Partner with Product, Design, and Data Science to validate accountant workflows and iterate based on feedback Participate in code review and help set the technical bar for a team that's still establishing its engineering practices Mentor other engineers as the team scales Here’s what we're looking for: 8+ years of professional software development experience Experience owning multi-quarter projects end-to-end — scoping, planning, execution, stakeholder management, and launch Strong platform/application engineering background: services, APIs, third-party integrations, data flows, observability Comfortable operating in an ambiguous, early-stage domain where the roadmap isn't fully written yet Ruby on Rails experience strongly preferred; experience with 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 — able to explain technical tradeoffs to both engineers and cross-functional partners AI-native mindset, with AI tools naturally embedded in your daily engineering workflow (code generation, review, debugging, documentation) Our cash compensati