Gusto
Staff Software Engineer, Gustie Assist
Denver, CO - Hybrid +3 · Staff · Full-time · Posted Aug 14, 2026
- Location
- Denver, CO - Hybrid
New York, NY - Hybrid
San Francisco, CA - Hybrid
San Francisco, CA - Hybrid - Experience
- Typically 8+ years of software engineering experience, owning systems end-to-end.
About the job
Build and operate Otto, Gusto’s AI support-agent platform, spanning its runtime, tools, backend, advocate-facing experience, and reliability systems.
What you'll do
- Own end-to-end platform development, including the agent runtime, action layer, Rails/GraphQL backend, and advocate-facing product.
- Enable safe agent actions with human approval, secure permissions, and auditable identity controls.
- Build evaluation and monitoring systems, improve the agent using LLMs and advocate feedback, and mentor engineers.
What they ask for
- Production experience building and shipping LLM-powered or agentic systems, including tool-calling/agents, retrieval, or evaluations.
- Strong full-stack skills across backend services, LLM runtimes, and customer-facing products.
- Experience owning multi-quarter projects with measurable user impact at scale.
- Sound judgment about safety and blast radius, plus ability to mentor engineers.
Nice to have
- Experience with agent frameworks, LLM-as-judge, retrieval, or MCP-style tool architectures.
- Experience with Ruby on Rails and/or JavaScript/React; familiarity with GraphQL and federated backends.
Tools
LLMs, Rails, GraphQL, Ruby on Rails, JavaScript, React, MCP
AI focus
Build and improve a production AI agent, including its runtime, tool use, retrieval, evaluation, observability, and feedback loops; ensure its actions are safe and reliable.
Model-written summary · the original posting is authoritative