Senior Software Engineer (Foundation Agents)

Join the Foundation Agents team as a Senior Software Engineer, where you'll take ownership of measuring and improving agent quality, design and build agent knowledge and evaluation infrastructure, lead error analysis on agent behavior, and drive the AI platform's reliability and quality roadmap forward. You'll also mentor engineers on the team and have a significant impact on the reliability and quality of every agent built on the platform.

You're strong in the backend and comfortable owning platform-level systems

About Fieldguide

• You multiply the people around you, not just your own output
• Frontier problems: You're working on open problems in agent reliability that don't have established playbooks yet
• Evaluation as a craft: Evals and error analysis are core to how this team improves quality, not an afterthought
• Platform-level impact: Your work shapes the reliability and quality of every agent built on top of it

Responsibilities

• Ownership of the evaluation strategy and error-analysis practice, shaping how the team measures and improves agent quality.
• Designing and building agent knowledge and evaluation infrastructure for Fieldguide's long-horizon agents.
• Leading error analysis on agent behavior, turning findings into concrete platform-level reliability improvements.
• You think in evals and error analysis as a discipline; you dig into why an agent failed and fix the systemic cause
• You've built AI products end-to-end, with real ownership over agent quality outcomes
• Demonstrated experience building evals and performing error analysis

Requirements

• You're motivated by long-horizon agents that do real work in production
• Backend engineering experience
• Strong experience working on an AI platform
• 1+ years working specifically on agents
• Long-horizon agents: Working on agents that do real, sustained work
• Frontend experience
• Distributed systems experience
• Strong platform engineering skills

Pay

USD 225,000 - 250,000