LLM Fine-Tuning vs RAG: When to Use Which

A practical decision framework for teams building with LLMs — with real trade-offs, cost analysis, and when to combine both

Table of Contents

• The Core Question
• What Is RAG?
• What Is Fine-Tuning?
• Head-to-Head Comparison
• When to Choose RAG
• When to Choose Fine-Tuning
• When …

Why GenAI?

Generative AI has completely changed how I think about software, creativity, and problem-solving. Over the past year, I've gone deep into the world of large language models, prompt engineering, retrieval-augmented generation, fine-tuning, and AI agents. The pace of change is incredible, and I wanted a place to document …