Hands-on LabIntermediatePro

LLM-as-a-Judge

Learn to evaluate open-ended AI output by building an LLM judge from scratch.

6 labsabout 1 hUpdated Jun 2026

What you'll build

See why keyword rules fail on open-ended output
Build an LLM judge that scores replies on a rubric
Validate the judge against human labels
Harden it against bias and ship an evaluation report

Curriculum

6 labs, about 1 h

  1. 1

    Why rules can't grade this

    Open-ended output has no single correct answer, so keyword rules fail. Name the qualities a judge will score instead.

    4 min

    Pro
  2. 2

    Your first judge call

    Call a frontier model from the sandbox and ask it to judge one support reply with a simple yes or no verdict.

    12 min

    Pro
  3. 3

    A rubric and a score

    Give the judge a three-part rubric and have it score every reply as parseable JSON instead of a yes or no.

    14 min

    Pro
  4. 4

    Who judges the judge?

    Measure whether the judge can be trusted by comparing its scores against human labels and reporting the agreement rate.

    14 min

    Pro
  5. 5

    Bias and reliability

    Learn the common LLM-judge biases and harden the judge with reason-first scoring and temperature 0, then document one failure mode.

    15 min

    Pro
  6. 6

    Capstone: ship the judge

    Turn the judge's scores and its agreement with humans into a short, honest evaluation report, and confirm the suite runs end to end.

    15 min

    Pro

Your instructor

ES

Elvis Saravia

Founder, DAIR.AI

Elvis founded DAIR.AI and wrote the Prompt Engineering Guide, one of the most widely used references on working with language models. He has worked at companies like Meta AI and Elastic, and specializes in AI agents, RAG, and harness engineering.

How labs work

Live workspace

You run the real tools in a browser workspace. Nothing to install.

Checkpoints

Each lab checks your files and output, then unlocks the next one.

Your work stays

The workspace persists between labs so you finish with a project.

Questions

$49 / moEvery lab included