AI Engineer, Brex

• Strong track record of shipping customer-facing features end-to-end across both backend and frontend — you don't bounce work over a wall, and you've built enough of each to have real opinions
• Product mindset: you reason about users, workflows, and outcomes first, and treat the system as the means to an end. Comfort with ambiguity and willingness to talk to customers directly
• Strong bias towards action — you've operated in environments where the next thing to build wasn't handed to you in a ticket, and you've shipped things that didn't exist before
• Comfort working across team boundaries and pushing back on decisions outside your direct ownership when the seam isn't right — agent design, UX, data model, all fair game
• Strong backend foundation — system design, data modeling, API shape — and the disposition to ship the UI yourself when that's what the user problem needs, rather than handing it off

Desirable

• AI Engineering at Brex is redefining how businesses run their finances by building intelligent, autonomous systems directly into the Brex platform
• Our teams develop AI agents that don’t just surface insights—they take action, optimizing spend, managing workflows, and making real-time decisions on behalf of our customers
• By deeply integrating proprietary financial data with product and platform infrastructure, we’re turning complex financial operations into simple, automated experiences and setting a new standard for how modern finance works
• You'll be a product engineer building Brex's Audit Agent — an agentic system that reviews customer spend at scale and replaces the manual work traditionally done by BPO teams
• The agent itself reasons; the surrounding product harness is what makes that reasoning useful, trustworthy, and operable for real customers
• That product harness is where you'll live. You'll design and ship the workflows, surfaces, and data flows that turn the agent's output into something a reviewer can trust and act on — from the reviewer experience itself, to the contracts with Brex's financial system of record, to the feedback loops that make the agent better over time
• You'll move fluidly between backend and frontend as the work demands, picking the right altitude for the problem rather than defending a layer
• This role sits between deep agent design and the customer-facing UI, and it leans toward whichever side the next user problem lives on
• You'll partner closely with the engineers driving each — translating ambiguous product requirements into shipped features, pushing back when the design isn't right, and treating the seam between agent reasoning and human workflow as a first-class product surface
• The majority of your work will be backend: system design, data modeling, API shape
• A meaningful minority will be on the UI itself, where you'll build alongside our frontend engineers when that's where the next user problem lives
• Build and ship customer-facing features in production — from sketch to rollout to iteration based on real customer feedback
• Define the data contracts between the agent and the rest of Brex's financial system of record, and evolve them as the product gets sharper
• Stand up feedback and evaluation loops that let us quickly gather product signals and close them with product fixes — better signals, better surfaces, better workflows
• Run experiments on customer-facing behavior (UI flows, prompt-driven product changes, new review modes) and make calls based on what the data says
• Talk to customers and reviewers directly, bring what you learn back into the product, and prioritize what to build next on the team