How I Structure a FastAPI Backend with LLM Features (From a Real Project) I Don’t Start With Endpoints Anymore When I used to start backend projects, I’d jump straight into writing routes. That worked… until the project grew. Now, I start with something else: “How will this project fall apart in 3 months?” Because it will — especially if you’re using LLMs. You’ll start seeing: prompts copied across files random LLM calls inside endpoints parsing logic that no one wants to touch “temporary” hacks that become permanent So these days, I focus heavily on structure first , features second. This post is how I structured a FastAPI backend with LLM integration for a real estate consultant system — and what actually held up. FastAPI vs Express — Different Problems Coming from Node.js + Express, I was used to this: routes/ controllers/ services/ models/ Enter fullscreen mode Exit fullscreen mode Flexible, simple… and easy to mess up.…