Product engineer, full stack

judgmentlabs; San Francisco (CA); On-site; USD 140,000 - 170,000; Full time

Job summary

Judgment is the learning infrastructure for AI agents. As a Product Engineer — Full Stack, you will own problems end-to-end: talking to customers, defining what to build, building it, and iterating until it's great.

You will design and ship production-ready systems, from data layer to UI, with a bias for fast iteration and measurable impact. You will collaborate across teams to turn insights into robust platform features that scale with customer needs.

Qualifications

• Experience building and scaling end-to-end production systems.
• Ability to work with customers to understand needs.
• Excellent communication across technical and non-technical audiences.

Responsibilities

• Investigation interfaces: design how engineers understand what their systems did and why.
• Verification: build the platform for verifying system changes with simulated environments.
• The improvement loop: turn production data into datasets, evaluations, and regression checks.
• The platform underneath: workspaces, roles, permissions, billing, usage, and limits for teams.

Skills

End-to-end systems

Analytical thinking

Hands-on builder

Customer collaboration

Clear communication

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:

1. We ingest everything your agents do in production: traces, tool calls, decisions, outcomes

2. Judgment turns that raw experience into structured signals: failure modes, behaviors, rubrics, evals

3. 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