Member of Technical Staff, Product Engineer/Full Stack
Judgment Labs, San Francisco
About the job
About judgment
Judgment Labs is building the infrastructure for continual learning in long-horizon AI agents.
We turn long agent trajectories into clean, structured data for evals, labeling, rubric generation, context engineering, and RL workflows. Instead of only showing teams what happened, Judgment helps decide what matters, what should be learned from, and how that learning should flow back into the agent.
We’ve raised $32M across two rounds led by Lightspeed.
The role
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’ll do
- 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.