Eval Pipeline Architecture
Why public benchmarks do not transfer to your workload, how to build a model-selection eval, and why cost per successful task beats price per token.
Evals (evaluations) measure how well your LLM application performs on a representative task dataset. Without evals, prompt changes and model upgrades are guesswork. Evaluation types: exact match (for structured outputs), semantic similarity (embeddings), LLM-as-judge (for quality), and human review (gold standard). A regression suite detects when prompt tweaks break existing behaviour. Tools: OpenAI Evals, LangSmith, Phoenix, and custom frameworks.
The pipeline
Each stage in order — click any step to read what it does.
Interactive Pipeline Flow
Architecture diagrams
Components of an LLM application evaluation pipeline.
Key design decisions
The trade-offs worth knowing before you build this.
Define what success looks like before writing a single prompt. 50 high-quality input-expected pairs from real use cases are more valuable than 1000 synthetically generated ones.
LLM judges have bias toward verbose, confident-sounding responses. Calibrate your judge with human-labeled anchor examples. Use multiple judge models and average scores for high-stakes evaluations.
Every prompt change, model upgrade, or retrieval modification can improve some cases while breaking others. Run your eval suite in CI and gate merges on no regression >2% in pass rate.
Continue reading
All LLM Model Landscape articles →GPT: OpenAI's Model Family in Practice
The GPT-6 tiers, what reasoning effort replaced, when to use the Responses API over Chat Completions, how the bill is calculated, and what is different on Azure.
Claude: Anthropic's Model Family in Practice
The four Claude tiers, adaptive thinking and effort, the tool-use rules that differ from other providers, prompt caching, and where you can run it.
Llama: Open-Weight Models for Production
The Llama lineup and licence, serving with Ollama and vLLM, GPU memory sizing, and an honest look at when a hosted API is still the better choice.
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