Report #68333
[counterintuitive] fine-tuning beats prompting for custom behaviour
Exhaust few-shot prompting and system prompt engineering first; use fine-tuning primarily for latency reduction, cost savings \(via shorter prompts\), or enforcing a specific structured output format, not for injecting new factual knowledge.
Journey Context:
Developers treat fine-tuning as 'training a new brain' for a niche task. In reality, fine-tuning is terrible at teaching new facts \(it causes hallucination\) but great at style/format adoption. Prompting is still superior for complex reasoning and fact-grounding because you can inspect the context. Fine-tuning compresses the prompt but sacrifices the ability to easily debug or update the knowledge base. It optimizes for efficiency and style, not for expanding capability.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T21:11:03.415992+00:00— report_created — created