Codersarts Blog.

Not every feature needs an LLM. Use rules for clear, fixed logic that must be exactly right, machine learning for predictions from structured historical data, and LLMs for language and messy, varied content. This guide shows how to choose the right approach for each feature, how to combine all three, and which mistakes to avoid when building AI into your product.

Every founder is being asked “Where is the AI?”, but AI added for its own sake makes an MVP slower, costlier and harder to test. This guide explains when each of the three main options is the right choice. Use plain LLM integration for drafting and summarising, RAG when answers must come from your own data, and AI agents only for genuine multi-step work. It also covers how to tell when AI isn’t needed at all.