Senior Software Engineer, Operational AI

About the role

Brex is hiring a Senior Software Engineer for its Operational AI team in São Paulo, focused on the Agents Platform: the internal platform used to build, evaluate and run AI agents in production across onboarding, support and go-to-market workflows.

What you'll do

• Own the technical direction and roadmap of the Agents Platform together with Operational AI leadership and partner teams.
• Build platform capabilities such as tool calling, multi-step agent loops, multi-turn execution and secure access to internal data and services.
• Evolve evaluation and quality systems, including datasets, labeling, run comparison and regression testing for non-deterministic systems.
• Improve reliability, security and observability for business-critical flows, covering durable async/batch execution, authorization, cost attribution and incident response.
• Drive adoption through clear contracts, paved roads and documentation, and mentor engineers via design and code reviews.

Requirements

• 5+ years of software engineering experience building and operating production backend systems.
• Production experience shipping LLM-powered systems: orchestrating model calls, structured outputs and quality evaluation.
• Hands-on daily use of AI coding tools such as Claude Code or Cursor.
• Experience with distributed and asynchronous systems (retries, idempotency, backpressure, observability) and a platform/developer-experience mindset.
• Strong communication and English proficiency; interviews are conducted in English.

Hybrid role: three coordinated office days per week (Monday, Wednesday, Thursday).