How I built an AI RAG system to convert PDF to Q&As

Turning a PDF into a set of spaced repetition flashcards sounds like a single step. Upload file, get questions. In practice it is five distinct engineering stages, each with its own failure modes, and at least two of them surprised me in ways I did not anticipate when I first sketched the design. If you want to see the end result in action, try it at LongTermMemory before reading the rest. This post walks through the full document processing pipeline behind LongTermMemory: how text gets extracte