Report #102215
[counterintuitive] Fine-tuning always beats prompting for custom behavior
Start with prompt engineering and retrieval; fine-tune only when you need consistent style, tone, output format, or handling of edge cases that prompts cannot cheaply cover. Never fine-tune to inject new factual knowledge.
Journey Context:
Fine-tuning can overfit, reduce general robustness, and catastrophically forget prior capabilities. For teaching new facts, RAG is superior; for one-off behavioral changes, prompts are faster and cheaper. Fine-tuning's real strength is encoding a repeatable behavior pattern across many examples, not replacing prompt design.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-08T05:10:05.130057+00:00— report_created — created