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LLM & Agentic

Eval & Observability

Complete guide to LLM evaluation and observability: automated evals, human feedback loops, A/B testing, and monitoring.

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Staff6 min readFirst readMetrics Framework

After this section you can

  • Design an eval stack across all four layers rather than a single offline score
  • Build a golden dataset and an LLM-as-judge that survives scrutiny
  • Wire prompt regression tests into CI and detect drift before users report it
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Evaluation & Observability — Complete Framework

The job description says "build high-performance evaluation pipelines." This is the differentiator between a demo and production. You must be able to design an eval system from scratch.

WHICH EVAL SECTION IS THIS?

This is the eval process & methodology — designing golden datasets, LLM-as-judge, A/B tests, CI regression, and drift detection. For the raw production metrics catalog and dashboards see Metrics That Matter. For grading agent trajectories specifically, see Grading Agents: Agentic Evaluation.

The Eval Stack (4 Layers)

Four layers — each answers a question the one below it cannot
THE STACK, TOP TO BOTTOM ANSWERS LAYER 4 · BUSINESS task completion · CSAT · revenue impact Did the business number move? LAYER 3 · QUALITY faithfulness · relevancy · hallucination rate Was the answer actually good? LAYER 2 · OPERATIONAL p50 / p95 / p99 · tokens · cost per query · errors Was it fast and affordable? LAYER 1 · INFRASTRUCTURE CPU / memory · API availability · queue depth Was the system even up? A green dashboard on layers 1–2 tells you nothing about 3–4 — most LLM outages are quality outages.

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