Staff Software Engineer, Gustie Assist

United States Digital Space LLC; Denver, California (CO, MO); Hybrid; USD 180,000 - 240,000; Full time

Job summary

Symmetry is hiring for a senior engineering role focused on building and scaling an LLM-powered agent platform. You will own end-to-end system design across the runtime, tool layer, backend, and advocate-facing frontend, driving measurable impact for customers.

You will collaborate with product, data, design, and CX teams, mentor engineers, and help shape safe, scalable AI foundations in a high-autonomy environment.

Qualifications

• 8+ years of software engineering experience, owning systems end-to-end.
• Shipped LLM-powered or agentic systems in production, including tool-calling/agents, retrieval, or evals.
• Strong full-stack capabilities across backend, LLM runtime, and customer-facing product.

Responsibilities

• Design and build across the Otto platform, including runtime, tool layer, backend, and UX end-to-end.
• Expand agent capabilities with safe, auditable actions and human-in-the-loop approvals.
• Develop eval and observability systems to enable weekly production updates without regressions.
• Work with LLMs on prompting, tooling, retrieval, and feedback loops.

Skills

8+ years exp

Full-stack

LLM/agentic systems

Mentoring engineers

Tools

Ruby on Rails

JavaScript/React

GraphQL

Job description

About the company

At the company, 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) so because everyone who helps build the company 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 the company. 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.

Gustie Assist builds Otto, the AI agent that the company's support advocates rely on to solve customers' hardest payroll, benefits, and compliance problems. When a small business hits a wall and reaches out, the advocate turns to Otto: it reasons over the customer's full context, answers in the moment, and increasingly takes real actions across the company's systems on the advocate's behalf to make the customer whole. We're a small platform team building an agent that reasons, acts, and has to get it right when the stakes are someone's payroll.

This is unusually broad, hands-on applied-AI work: you'll own an LLM agent runtime and the full stack around it, including the tool layer that lets it act over the company's systems, the Rails/GraphQL backend, the advocate-facing frontend, and the eval system that keeps it trustworthy while it touches live customer accounts. We keep the path from idea to production short, and measure ourselves on customer outcomes, not model novelty.

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

• Design and build across the Otto platform, including the runtime and agent graph, the tool/action layer, the Rails/GraphQL backend, and the advocate-facing experience, owning a meaningful slice end-to-end

• Expand what the agent can safely do: autonomous, tool-using actions with human-in-the-loop approval, built on a secure, auditable identity and permissions model

• Build the eval and observability systems (LLM-as-judge + deterministic scorers, offline gates and online production monitoring) that let us change the agent in production weekly without regressing correctness or escalation behavior

• Work directly with LLMs, including prompting, tool/function design, retrieval, and the feedback loops that turn real advocate interactions into a better Otto

• Partner closely with Product, Data, Design, and our CX teams to turn advocate and customer pain into shipped capabilities

• Mentor engineers and set the bar for how we build agentic systems responsibly and at scale

Here's what we're looking for:

• Typically 8+ years of software engineering experience, owning systems end-to-end

• You've built and shipped LLM-powered or agentic systems in production, including tool-calling/agents, retrieval, or evals, and you know where they break and how to make them reliable

• Strong full-stack range. Must be comfortable moving between backend services, an LLM runtime, and customer-facing product, and picking up whatever the problem needs

• Experience owning multi-quarter projects that make measurable user impact at scale

• Sound judgment about safety and blast radius when software takes real actions on real accounts

• Ability to mentor engineers and raise the bar around you

Also great to have:

• Experience with agent frameworks, evals/LLM-as-judge, retrieval, or MCP-style tool architectures

• Experience with Ruby on Rails and/or JavaScript/React (our stack), or the ability to ramp quickly

• Familiarity with GraphQL and federated backends

• Appreciation for a collaborative, test-driven, high-autonomy environment, and clear communication with engineering and business stakeholders

the company has physical office spaces in Denver, San Francisco, and New York City. Employees who are based in those locations will be expected to work from the office on designated days approximately 2-3 days per week (or more depending on role). The same office expectations apply to all Symmetry roles, the company's subsidiary, whose physical office is in Scottsdale.

Note: The San Francisco office expectations encompass both the San Francisco and San Jose metro areas.

When approved to work from a location other than a the company office, a secure, reliable, and consistent internet connection is required. This includes non-office days for hybrid employees.

Our customers come from all walks of life and so do we. We hire great people from a wide variety of backgrounds, not just because it's the right thing to do, but because it makes our company stronger. If you share our values and our enthusiasm for small businesses, you will find a home at the company.

the company is proud to be an equal opportunity employer. We do not discriminate in hiring or any employment decision based on race, color, religion, national origin, age, sex (including pregnancy, childbirth, or related medical conditions), marital status, ancestry, physical or mental disability, genetic information, veteran status, gender identity or expression, sexual orientation, or other applicable legally protected characteristic. the company considers qualified applicants with criminal histories, consistent with applicable federal, state and local law. the company is also committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. We want to see our candidates perform to the best of their ability. If you require a medical or religious accommodation at any time throughout your candidate journey, please fill out this form and a member of our team will get in touch with you.

the company takes security and protection of your personal information very seriously.

Personal information collected and processed as part of your the company application will be subject tothe company's Applicant Privacy Notice.