Product engineer, full stack

Judgment Labs; San Francisco, Northern (CA, KY); Hybrid; USD 140,000 - 180,000; Full time

Job summary

Judgment Labs is seeking a Product Engineer — Full Stack to own end-to-end production systems, from data layer to UI. You will engage with customers, define what to build, implement solutions, and iterate until the product is excellent.

You will design investigation interfaces, verification platforms, and workflows that turn production signals into actionable improvements, helping teams ship confidently across multiple environments.

Qualifications

• Experience building and scaling end-to-end production systems (data layer to UI).
• Strong technical problem-solving skills in fast-changing, ambiguous environments.
• Builder mindset with high agency and ability to ship.
• Comfort working directly with customers to understand needs and solve real-world problems.

Responsibilities

• Design and scale investigation interfaces to show engineers what systems did and why.
• Build a verification platform with hosted environments, replay trajectories, and monitors for unintended changes.
• Develop workflows that turn production data into datasets, evaluations, and regression checks for efficient fixes.
• Oversee the platform underneath: workspaces, roles, permissions, billing, usage across multiple environments.

Skills

End-to-end systems

Problem solving

Creative troubleshooting

Customer collaboration

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:

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