Startups · AI

Backend/Infra Engineer

Judgment Labs · San Francisco · On-site

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About Judgment Labs

Backed by Lightspeed.

About the role

We’re looking for a Senior Backend Engineer to own the systems that ingest, structure, evaluate, and serve agent experience data at production scale.

What they're looking for

  • Strong backend engineering experience building and operating production systems under real load
  • Excellent fundamentals in distributed systems, API design, data modeling, reliability, and performance
  • Experience working with high-volume event, trace, log, metric, or telemetry data
  • Strong intuition for data systems: query patterns, storage layout, indexing, partitioning, latency, correctness, and cost
  • Comfort owning systems beyond initial launch: debugging production issues, improving observability, scaling bottlenecks, and cleaning up abstractions as the product evolves
  • Ability to work across backend, data, product, and infrastructure boundaries rather than treating them as separate silos
More about this role

San Francisco · On Site · Full Time

Judgment Labs is building the infrastructure for continual learning in long-horizon AI agents.

The next generation of agents will not improve from prompts alone. They will improve from experience: the tasks they attempt, the tools they use, the mistakes they make, the edge cases they encounter, and the outcomes they produce in production. The hard part is turning that raw experience into high-quality data that can actually improve the system.

Judgment builds the infrastructure to do that. 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.

Databricks built the data infrastructure for analytics. Judgment is building the learning infrastructure for agents.

We’ve raised $30M+ from Lightspeed, SV Angel, Valor Equity Partners, and others.

We’re looking for a Senior Backend Engineer to own the systems that ingest, structure, evaluate, and serve agent experience data at production scale.

This role...

Read the full posting on Judgment Labs's site ↗

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