Chaining a few prompts together used to feel advanced. Then real applications hit reality: loops that need to retry, decisions that branch, state that has to persist across steps. A single prompt — or even a linear chain of them — just isn't built for that. That's the gap LangGraph was built …

At some point, every team building with LLMs hits the same fork in the road: do you get better results by writing a smarter prompt, or by actually retraining the model on your own data? It sounds like a technical detail, but the choice affects your cost, your timeline, and …