Staff Fullstack Engineer

uiAgent; New York (NY); On-site; USD 140,000 - 190,000; Full time

Benefits offered by this job

Equity

Cash bonus

Flat structure

Top-tier equipment

Healthcare

Team dinners

Manhattan office

Job summary

uiAgent is seeking a Staff Full Stack Engineer to own our systems end-to-end—from the React components users click to the Kubernetes pods processing requests. At this stage, you’ll move fluidly across the stack and own problems from UX to infra in a fast-moving startup.

You’ll build in React, Node.js, and cloud-native tech, collaborate in our Manhattan office, and ship features that scale for CPA workflows.

Qualifications

• Experience building production systems spanning frontend, backend, and infrastructure.
• Ability to design scalable APIs and data schemas for complex data.

Responsibilities

• Own frontend interfaces with React for data-rich UIs and dashboards.
• Architect and build Node.js microservices and scalable APIs.
• Own CI/CD, containerization, and cloud infrastructure on AWS.
• Collaborate with AI engineers to integrate LLM-powered features.
• Ship features end-to-end and keep systems running at scale.

Skills

Full-stack engineering

Frontend development

System design

AI integration mindset

In-person collaboration

Tools

React

Node.js

Kubernetes

AWS

PostgreSQL

Job description

uiAgent is building AI agents that are transforming how CPAs and accounting teams work. We’re pre-Series A with significant revenue, strong traction, and the kind of product-market fit that makes investors pay attention. The accounting industry is massive, underserved by technology, and ripe for disruption — and we’re already doing it.

Our team is small, sharp, and close-knit. We built this product over 18 months by being relentlessly resourceful, and we’re looking for someone who operates the same way.

The Role

We need a Staff Full Stack Engineer who can own entire systems end-to-end — from the React component a user clicks to the Kubernetes pod processing their request. At our stage, there’s no “that’s not my job.” You’ll move fluidly across the stack because that’s what building a real product at this stage demands.

• Frontend — You’ll build the interfaces that accountants and auditors use every day. This means complex, data-rich UIs in React — think multi-step workflows, real-time agent status views, document review tools, and dashboards that surface the right information at the right time. You care about UX as much as code quality, and you know how to make powerful tools feel simple.
• Backend & APIs — You’ll architect and build microservices in Node.js, design scalable APIs, and work with databases handling complex audit and financial data. You care about clean abstractions, thoughtful schema design, and systems that don’t fall over at scale.
• Infrastructure & DevOps — You’ll own CI/CD pipelines, containerization, cloud infrastructure on AWS, and observability. When a CPA firm runs 500 audits through our system simultaneously, you’re the reason it doesn’t break.
• AI Integration — You’ll work closely with our AI engineers to build the product surfaces around our agentic platform. This means integrating LLM-powered features into the application layer, designing how users interact with autonomous agents, and building the feedback loops that make our AI better over time. Deep ML experience isn’t required, but comfort working with AI systems and a genuine curiosity about the space is.

This isn’t a role where you’ll write tickets and hand them off. You’ll identify problems, design solutions, build them, ship them, and keep them running.

What We’re Looking For

• Depth across the stack. You’ve built and deployed production systems spanning frontend, backend, and infrastructure. You’re not a specialist reluctantly touching other layers — you genuinely enjoy the full picture and can make sound architectural decisions at every level.
• Frontend craft. You don’t just make things work, you make them work well. You’ve built complex, stateful UIs that real users depend on. You think about loading states, error handling, accessibility, and performance — not because someone told you to, but because you’ve seen what happens when you don’t.
• Strong engineering fundamentals. You have opinions about code quality, system design, and architecture. You hate spaghetti code because you’ve seen what it does to velocity at scale. You think in systems, not just features.
• Comfort around AI. You don’t need to train models, but you should be excited about building product around them. You understand how to integrate LLM outputs into user-facing experiences and can reason about the UX challenges that come with non-deterministic systems.
• Startup tempo. You thrive in environments where speed matters and context-switching is the norm. You’re self-directed and don’t need a project manager to tell you what’s important.
• In-person collaboration. We work together in our Manhattan office. Our best ideas come from whiteboarding sessions, fast feedback loops, and the kind of spontaneous problem-solving that doesn’t happen over Zoom.

What We Offer

• Substantial equity — meaningful ownership in a company with real traction and clear upside
• Competitive salary cash bonus
• Flat structure — you’ll work directly with the founders and have real influence on product and technical direction from day one
• Top-tier equipment — whatever you need to do your best work
• Healthcare, dental, vision, and commuter benefits
• Daily team dinners and a culture that actually enjoys spending time together
• A great office in Manhattan with a skyline view

Who We Are

We’re a team that takes the work seriously but doesn’t take ourselves too seriously. We’re direct with each other, we solve hard problems together, and we genuinely like hanging out. If you’re looking for a place where your work has outsized impact, where you’ll learn fast, and where you’re building something people actually use — we’d love to talk.