---
title: 'Product engineer, full stack at Judgment Labs'
canonical: 'https://feeny.ai/job/product-engineer-full-stack-judgment-labs-san-francisco-rzn6c0km6mxc'
type: 'job'
last_seen: '2026-09-10'
---

# Product engineer, full stack at Judgment Labs

- **Company:** Judgment Labs
- **Location:** San Francisco, CA
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-07-14
- **Last confirmed live:** 2026-09-10
- **Apply:** https://jobs.ashbyhq.com/judgmentlabs/6ce15269-8e97-4211-bee4-7435dd7ed45d

## Job description

Product Engineer — Full Stack Job Description

## The Role

Judgment is the learning infrastructure for AI agents. Agents in production don't improve from prompts alone. They improve from experience: the tasks they attempt, the mistakes they make, the edge cases they hit. Here's how it works:

- We ingest everything your agents do in production: traces, tool calls, decisions, outcomes
- Judgment turns that raw experience into structured signals: failure modes, behaviors, rubrics, evals
- Teams close the loop, shipping agent improvements validated against real production evidence

You'll own problems end-to-end: talking to customers, defining what to build, building it, and iterating until it's great. This is not a role where you implement specs handed down.

## What You Will Accomplish

- Investigation interfaces: Design how engineers understand what their systems did and why. Long traces, tool calls, decisions, failures. How do you make a complex sequence of events legible in minutes?
- Verification: Build the platform for verifying system changes: hosted simulated environments, trajectory replay, and monitors for unintended behavior changes.
- The improvement loop: Build the workflows that turn production data into datasets, evaluations, and regression checks, so the path from "found a problem" to "verified a fix" feels like one motion.
- The platform underneath: Workspaces, roles, permissions, billing, usage, and limits for teams running many workflows across many environments.

## What You'll Bring

- Experience building and scaling end-to-end production systems, from data layer to UI
- Strong technical problem-solving skills, especially in fast-changing, ambiguous environments
- A builder and tinkerer's mindset with high agency - you find creative ways to overcome obstacles and ship
- Comfort working directly with customers to understand their needs and solve real-world problems
- Excellent communication skills - clear, direct, and persuasive across technical and non-technical audiences

## About Judgment Labs

## Company Overview
- **One-liner**: Judgment Labs builds a continuous-improvement stack for AI agents, helping teams monitor, evaluate, and improve agent behavior in production.
- **Entity Type**: Private (Seed + Series A funded)
- **Headquarters**: San Francisco, California, United States
- **Founded**: 2025
- **Founders**: Alex Shan (CEO), Andrew Li (Chief Scientist), Joseph Camyre (CTO)

## Core Business
- **Primary industry**: AI Infrastructure / Agent Observability
- **Target customers**: B2B — AI-native companies and engineering teams building and deploying autonomous AI agents
- **Mission or purpose**: Provide the infrastructure for a future where billions of AI agents act autonomously, giving teams the tools to make their products better with every interaction.

## Products & Services
- **Behavior Discovery**: Automatically constructs and refines evaluation rubrics from verifiable signals, surfacing failure modes and usage patterns from unlabeled production trajectories.
- **AutoRubrics**: Automates the creation of evaluation criteria for agent behavior.
- **Agent Search**: Enables querying across agent trajectories at a behavioral level, beyond simple input/output keyword search.
- **Agent Judge**: Builds cheaper and more accurate trajectory-level evaluators using harnesses.
- **Slack & MCP Integrations**: Allows teams to investigate issues, run tests, and take action directly from Slack, Claude, Codex, Cursor, or any MCP client.

## Market Standing
- **Valuation/Market Cap**: Not disclosed
- **Key Metric**: $32M in total funding (Seed + Series A, announced May 2026)
- **Notable Investors/Partners**: Lightspeed Venture Partners (led both rounds), Nova Global, SV Angel, Valor Equity Partners, Dynamic. Key partner: James Alcorn (Partner at Lightspeed) sits on the board.
- **Growth Signals**: +400% YoY headcount growth (19 employees as of mid-2026); platform already in production at a growing list of agent-native companies; company describes customer traction as “extraordinary.”

## Competitive Advantages
- First-mover advantage in a new category: agent behavior monitoring (ABM) infrastructure, built specifically for deep, multi-step agent trajectories rather than simple chatbot input/output evals.
- Founders have deep domain expertise: CEO Alex Shan was an AI researcher at Stanford’s NLP group under Chris Manning; Chief Scientist Andrew Li was an early research hire at TogetherAI; CTO Joseph Camyre built large-scale infrastructure at Datadog.
- Product is already standardizing within agent-native startups, creating a network effect as more production data flows through the platform.

## Strategic Focus
- Aggressively hiring AI researchers and engineers in San Francisco.
- Expanding the forward-deployed engineering team to serve a growing customer base.
- Mission: “Give every team building agents the tools to make their products better with every interaction.”

## Why Work Here
- **Culture**: Described as fast-moving, high-agency, and intellectually ambitious — values critical thinking, questioning assumptions, and taking bold bets.
- **Work Policy**: On-site in San Francisco (all roles require physical presence at HQ).
- **Notable Perks**: Work at the frontier of AI agent infrastructure; join a small but rapidly growing team (19 people) backed by top-tier VCs; early employees will define the company’s trajectory and culture.
- **Engineering Culture**: Emphasis on research engineering, rapid prototyping, and productionizing cutting-edge AI evaluation methods.

## Sources
1. [judgmentlabs.ai](https://judgmentlabs.ai/)
2. [judgmentlabs.ai/careers](https://www.judgmentlabs.ai/careers)
3. [linkedin.com/company/judgmentlabs](https://www.linkedin.com/company/judgmentlabs)
4. [builtin.com](https://builtin.com/company/judgment-labs)
5. [businesswire.com](https://www.businesswire.com/news/home/20260512621556/en/Judgment-Labs-Closes-%2432M-in-Seed-and-Series-A-Funding-to-Build-the-Continuous-Improvement-Layer-for-AI-Agents)

## Other roles at Judgment Labs

- [Product engineer, Agent](https://feeny.ai/job/product-engineer-agent-judgment-labs-san-francisco-t4ryveqq2yns) — San Francisco, CA
- [Founding Account Executive](https://feeny.ai/job/founding-account-executive-judgment-labs-san-francisco-973j3geb8a8e) — San Francisco, CA
- [Backend/Infra Engineer](https://feeny.ai/job/backend-infra-engineer-judgment-labs-san-francisco-dpt1kesgk6d9) — San Francisco, CA
- [Applied AI Engineer](https://feeny.ai/job/applied-ai-engineer-judgment-labs-san-francisco-2c68arqvx3sp) — San Francisco, CA