Greenhouse ·
full-timeSenior Software Engineer, Operational AI
Brex · São Paulo, São Paulo, Brazil
Brex is an intelligent finance platform that provides corporate cards, banking, and spend management software to businesses globally. This role sits within the Operational AI team, which focuses on building internal systems that automate company-wide operations, such as KYC, onboarding, and customer support. As a Senior Software Engineer, you will lead the technical direction of the Agents Platform, the core infrastructure used to develop, deploy, and evaluate AI agents at the company. Your day-to-day responsibilities will involve designing platform capabilities like multi-step agent loops and tool calling, while ensuring these systems meet production-grade standards for reliability, security, and observability. You will also manage the evaluation frameworks required to measure non-deterministic AI performance and mentor other engineers. This position is well-suited for an experienced software engineer with a strong background in building scalable platforms and a deep interest in applying AI to automate complex business workflows. You should be comfortable owning technical roadmaps and collaborating across cross-functional teams to drive the adoption of AI-native developer workflows.
Why join us Brex is the intelligent finance platform that enables companies to spend smarter and move faster in more than 200 markets. By combining global corporate cards and banking with intuitive spend management, bill pay, and travel software, Brex enables founders and finance teams to accelerate operations, gain real-time visibility, and control spend effortlessly. Brex’s AI-native automation and world-class service eliminate manual expense and accounting tasks for customers so they can focus on what matters most. Tens of thousands of the world's best companies run on Brex, including DoorDash, Coinbase, Robinhood, Zoom, Plaid, Reddit, and SeatGeek. Working at Brex allows you to push your limits, challenge the status quo, and collaborate with some of the brightest minds in the industry. We’re committed to building a diverse team and inclusive culture and believe your potential should only be limited by how big you can dream. We make this a reality by empowering you with the tools, resources, and support you need to grow your career. Engineering at Brex Engineering at Brex is about building systems that scale with speed and intention. Our teams span Software, Data, Security, and IT, and operate with high autonomy and deep collaboration. We tackle hard technical problems, own our outcomes, and push for excellence at every level — from architecture to deployment. It’s an environment where engineering is a craft, and builders become leaders. What you'll do Brex's AI strategy has three pillars: Product AI builds AI into the products our customers use, Corporate AI gives every employee AI tools to work faster, and Operational AI builds the AI that runs the company. The Operational AI team owns the AI systems and internal platforms that make Brex's operations AI-native, from onboarding and KYC automation to AI-powered customer support. We're a small team with a large surface area, and our work directly shapes how fast Brex can onboard, serve, and grow its customers. As a Senior Software Engineer on the team, you'll focus on Agents Platform, Brex's internal platform for building, evaluating, and running AI agents in production. It already powers critical automations in customer onboarding and AI tools for our sales and customer success teams. You'll own its technical direction, help it evolve from simple workflows into agents that take action, and make it the default way Brex ships AI into its operations. Where you'll work This role will be based in our São Paulo office. We are a hybrid environment that combines the energy and connections of being in the office with the benefits and flexibility of working from home. We currently require a minimum of three coordinated days in the office per week: Monday, Wednesday, and Thursday. As a perk, we also have up to four weeks per year of fully remote work. Responsibilities Own the technical direction and roadmap of Agents Platform, partnering with Operational AI leadership and the teams that build on it to decide what the platform should do next. Design and build new platform capabilities, including tool calling, multi-step agent loops, multi-turn and conversational execution, and secure access to internal Brex data and services. Evolve the evaluation and quality system, from datasets and labeling to run comparison and regression testing, so teams can measure and improve non-deterministic systems with production-grade rigor. Strengthen the reliability, security, and observability of systems in business-critical flows like customer onboarding, including durable async and batch execution, authorization, cost attribution, and incident response. Partner with engineering, operations, and go-to-market teams to launch and scale high-impact agents, translating how they work into clear platform requirements. Drive adoption by making the platform easy to build on through clear contracts, paved roads, documentation, and AI-native developer workflows. Mentor engineers on the team and across Brex through design reviews, code reviews, and pairing, and help grow the team's technical bench. Requirements 5+ years of professional software engineering experience, with a track record of designing, building, and operating reliable production backend systems. Deep, hands-on experience using AI coding tools like Claude Code or Cursor in your daily work, with the judgment to ship faster without lowering the quality bar. Hands-on experience shipping LLM-powered systems to production, beyond prototypes: orchestrating model calls, enforcing structured outputs, and evaluating quality over time. Experience with distributed and asynchronous systems and the reliability concerns that come with them, such as retries, idempotency, backpressure, and observability. A platform mindset: you've built shared infrastructure, developer tooling, or paved roads that other engineers adopt, and you care about developer experience and secure-by-default design. High ownership and operational excellence, including on-
| Role | Senior Software Engineer, Operational AI |
|---|---|
| Company | Brex |
| Location | São Paulo, São Paulo, Brazil |
| Type | internship |
| Compensation | Not disclosed |
| Posted | 2026-10-01 |
| Deadline | Rolling |
Typical process for this type of role
A general guide — the exact steps for this specific listing may vary; check the original posting for details.
- 1ApplicationSubmit your resume through the apply link.
- 2ScreeningRecruiter reviews your background against the role.
- 3AssessmentA technical test, assignment, or coding round, depending on the role.
- 4Interview(s)One or more rounds with the hiring team.
- 5OfferOffer letter with compensation and start date.
Before you apply
0/4About Brex
Brex is a finance software platform that provides integrated financial services and software to help businesses manage their operations. The company serves over 35,000 customers, including startups, mid-size companies, and enterprises, as well as ecommerce brands. Its platform offers a suite of tools designed to automate financial workflows, including corporate cards, expense management, bill pay, accounting automation, and banking and treasury services. By utilizing AI-powered controls and integrations, Brex aims to help organizations manage spending, automate manual tasks, and operate globally across more than 120 countries. The platform is designed to support companies through various stages of growth, from initial launch to scaling operations.
More at Brex
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