Fine-tuning vs RAG vs prompting: when each is the right tool

invalid@example.com (Aior), Aior
Fri, 01 May 2026 00:42:14 +0000
Model Training

The decision that wastes the most money​
"Should we fine-tune?" is one of the most-asked, most-overdone decisions in LLM work. Fine-tuning is expensive, locks you into a snapshot of a model, and is often the wrong answer to a problem that prompting + RAG could have solved cheaper. Below is the framing we use.

The hierarchy: cheaper to more expensive[/HEADING>

1. Better prompting — almost always tried first...