Senior Software Engineer, Agents (Foundation Agents)

About the Role

The Foundation Agents team stewards the long-horizon agents powering the Fieldguide AI platform. We work at the frontier of AI product development: agent knowledge, evaluations, and improving quality and reliability at scale. As a Senior Software Engineer, Agents, you'll take ownership of how the team measures and improves agent quality, and help drive the platform forward.

What You’ll Own

• Evals strategy and error-analysis practice, shaping how the team measures and improves agent quality
• Design and build agent knowledge and evaluation infrastructure for Fieldguide's long-horizon agents
• Lead error analysis on agent behavior, turning findings into concrete platform-level reliability improvements
• Build and harden backend systems that support agent execution, evaluation, and monitoring at scale
• Drive the AI platform's reliability and quality roadmap forward, working closely with the broader AI team
• Mentor engineers on the team, raising the bar on eval rigor and error-analysis practice

Who You Are

• You've built AI products end-to-end, with real ownership over agent quality outcomes
• You think in evals and error analysis as a discipline; you dig into why an agent failed and fix the systemic cause
• You're strong in the backend and comfortable owning platform-level systems
• You're motivated by long-horizon agents that do real work in production
• You multiply the people around you, not just your own output

Must-have

• 1+ years working specifically on agents
• Strong experience working on an AI platform
• Demonstrated experience building evals and performing error analysis
• Backend engineering experience

Nice-to-have

• Strong platform engineering skills
• Frontend experience
• Distributed systems experience

What Should Excite You

• Long-horizon agents: Working on agents that do real, sustained work
• 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
• Frontier problems: You're working on open problems in agent reliability that don't have established playbooks yet

Benefits

• Competitive compensation with equity
• Comprehensive health and wellness benefits
• Flexible time off and work schedules
• Technology reimbursements
• 401(k) plan
• Twice-yearly in-person offsites across the U.S.
• Wellness benefits starting on your first day