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codex · operators · Hamel Husain

Hamel Husain

Hamel Husain is an independent AI engineer who has spent the better part of a decade teaching and researching how to build reliable LLM applications. He co-created the AI Evals for Engineers and PMs course with Shreya Shankar, which has trained more than 4,500 practitioners from over 500 companies including OpenAI, Anthropic, and Google. His primary research focus is the gap between how teams approach evaluation in theory and what the process actually needs to surface real failure modes. He draws from hands-on work with more than 50 companies to identify recurring mistakes in how AI product teams build and use evals.

Operating themes

Insights · 16

Tier B · ai-native · leadership
Appoint one trusted-taste expert as the eval benevolent dictator, committees stall the loop
Tier B · ai-engineering
Error analysis is the most-skipped step in AI evals and gives the most leverage per hour invested
Tier B · engineering-ai-eng · ai-native
An eval tool that skips data exploration before evaluator selection produces premature, bundled metrics that miss the real failure modes.
Tier A · ai-native · engineering
Evals are systematic data analysis on your LLM application, start with error analysis, not tests
Tier B · engineering · ai-native
When a team says an AI product is hard to eval, the bottleneck is product design, not eval methodology
Tier B · ai-native · engineering
Binary pass/fail annotation produces better quality than Likert scales by forcing judgment on uncertain cases
Tier B · engineering · ai-native
Eval tooling anchors teams on generic automated metrics before they have examined enough outputs to know what actually fails
Tier B · ai-native · engineering
Excess context in LLM judge prompts degrades accuracy; judges need only the evidence relevant to the specific failure
Tier B · ai-native · engineering
Route classification tasks to a small model when confident and a large model when uncertain to preserve accuracy while cutting inference cost
Tier B · ai-native · engineering
Most LLM evaluation failures trace to product design problems upstream of the model, not model capability
Tier B · ai-native · engineering
Optimize retrieval and context before touching systems, and post-train only after exhausting both
Tier B · ai-native · engineering
Automated eval agents cannot detect failures that require your product's definition of good user experience
Tier B · ai-native · engineering
Teams must annotate raw LLM traces to discover failure modes before applying automated evaluation
Tier A · ai-native · engineering
Build LLM-as-judge as binary true/false, one judge per pesky failure mode, and validate against human labels
Tier A · ai-native · research-discovery
Sample 100+ traces, write one free-form note per trace, let an LLM cluster the notes, humans first, machines second
Tier B · engineering · ai-native
Evals close the harness improvement loop; treating them as a post-deployment quality check removes the signal that guides agent system improvement
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