Senior Software Engineer, AI - Simulation

Job Description

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. AI at Brex 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. What you’ll do You’ll own Brex’s simulation and validation platform for AI-powered products. Your mandate is simple and unforgiving: ensure that every AI surface at Brex is continuously scrutinized under extreme, realistic conditions — and that teams can ship with confidence because of it. You’ll build a system that uses synthetic data and scenario generation as a recursive self-improvement loop. Product teams will rely on it to catch regressions before customers do, to validate new capabilities safely, and to evolve prompts and agent behavior continuously. This platform will run against isolated, ephemeral environments that mirror production closely enough to matter. This is not a research role. It’s about exercising real products, breaking them creatively, and forcing the organization to get better. Where you’ll work This role will be based in our San Francisco 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 require 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! Res

Required Skills