Frontend Full Stack Staff Software Engineer, AI Platform Experiences

Gusto•Seattle, NY

17h•Hybrid

About The Position

We're hiring an experienced full stack engineer to help small businesses work better with AI. You'll build Gus, Gusto's AI-powered assistant, and create scalable solutions that serve millions of users. As a Software Engineer at this level, you'll own projects end-to-end from initial specs to deployed features—working at the intersection of modern AI capabilities and real business needs. The Core Experience - AI Experiences team owns Gus, Gusto's AI-powered assistant, and the platform that enables teams across Gusto to deliver AI-native experiences to customers across web, mobile, voice, email, and agent-based channels. You'll work within Gusto's AI platform infrastructure, collaborating closely with sister teams who own the underlying agent framework. Your focus is building experiences and enabling product teams to extend and scale within the platform. This work is directly tied to Gusto's top priorities. We operate with fast iteration cycles, deep cross-functional collaboration, and high ownership.

Requirements

8+ years of software development experience, with 4+ years building scalable platforms or high-impact customer-facing products
Strong foundation in front-end engineering and modern web technologies (Ruby on Rails, React, GraphQL, or similar full-stack frameworks) with ability to build well-structured, maintainable code
Track record of owning multi-quarter projects that solve complex engineering problems and deliver measurable customer impact at scale
Experience building internal platforms or developer-facing infrastructure that enables other teams to self-serve and ship AI-powered features
Excellent cross-functional communication skills with ability to mentor engineers and collaborate effectively across teams and stakeholders
Product-minded, customer-facing engineering approach with passion for creating great customer experiences and ownership over performance, reliability, and quality

Nice To Haves

AI platform development experience or strong learning orientation toward AI technologies, patterns, and frameworks (orchestration, evals, prompt systems—not ML model development)

Responsibilities

Architect, build, and test technologies supporting AI experiences within Gusto's product suite
Create standardized, self-serve patterns that enable product teams to extend Gus across web, voice, email, and agent-based experiences
Collaborate with ML and product teams on prompt engineering, clarifying question flows, and escalation logic—using A/B tests and data to drive improvements
Mentor engineers on complex technical challenges in AI, scalability, and platform infrastructure
Help scale a large Ruby/Rails and React application serving millions of users
Work with Product, Design, Security, and Technical Operations teams to understand customer needs, develop solutions, and launch features
Build customer-facing products end-to-end that customers rely on every day