Senior Software Engineer, Agents (Foundation Agents)

About Us Fieldguide is establishing a new state of trust for global commerce and capital markets by automating and streamlining the work of assurance and audit practitioners—specifically in cybersecurity, privacy, and financial audits. We build software for the people who enable trust between businesses. We're based in San Francisco, CA, and backed by Goldman Sachs Alternatives, Bessemer Venture Partners, 8VC, Floodgate, Y Combinator, and more. Over 50 of the top 100 accounting and consulting firms trust Fieldguide to power mission-critical work. 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 Experience 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 Our Values Fearless — Inspire and break down seemingly impossible walls Fast — Launch fast with excellence; iterate to perfection Lovable — Deliver happiness and 11-star experiences Owners — Execute and run the business with ownership Win-win — Create mutual value and earn trust for life Inclusive — Scale the best ideas with inclusive teams