JEV ARCHITECTURE GUIDE

Jev vs LLM vs classifier: which should you use?

Compare TypeSafe Jev with generative LLMs, deterministic rules, and task-specific classifiers by output shape, task fit, uncertainty, latency, and operational control.

Updated 2026-09-238–12 min
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1. Start with the output contract

Jev returns a typed Choice, Score, or Noul result over options you declare. A generative LLM returns tokens. A classifier returns labels from a fixed training target. Ordinary code returns an exact result from rules. Choose the interface your application actually needs.

ToolBest fitOutputMain risk
JevBounded semantic judgmentChoice / Score / NoulTyped but still possibly wrong
Generative LLMGeneration and extended reasoningText or structured outputOutput drift and parsing failure
Deterministic codeExact rules and factsExact resultRules miss semantic ambiguity
Dedicated classifierStable, high-volume label taskFixed labels and probabilitiesTraining data and model operations
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2. Use Jev for bounded semantic judgment

Routing, ranking, labeling, relevance, and risk bands are strong candidates when the right answer depends on meaning rather than a hard lookup. Your code should still validate the response, set thresholds, and own every side effect.

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3. Keep generation and long reasoning with an LLM

Writing, summarization, translation, coding, planning, and open-ended dialogue need outputs Jev is intentionally not designed to produce. A useful hybrid pattern lets Jev select a path or gate a request, then lets a generative model do the work that creates new text.

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4. Prefer rules or a classifier when they are enough

Permissions, arithmetic, schema checks, allowlists, and exact policy belong in code. A dedicated classifier can be attractive for a mature high-volume task with representative labels, a stable taxonomy, and a team able to train, deploy, and monitor it.

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5. Evaluate the complete system

Do not compare headline speed or price alone. Measure decision quality on your own labeled cases, end-to-end latency, provider failures, review rate, cost of mistakes, calibration by risk band, and how quickly the team can update the decision contract.