K-Means, K-Gone: Sparse Coding and the Retrieval Bottleneck
Indexing is where many retrieval systems quietly become expensive. The demo looks harmless: upload documents, create embeddings, ask questions, receive answers with citations. Then the corpus starts behaving like a real business corpus. Policies change. Product pages are rewritten. Compliance documents are replaced. Support tickets arrive every hour. The retrieval layer must keep up, and suddenly the glamorous RAG stack is waiting for the plumbing to rebuild itself. As usual, the least photogenic component is the one holding the invoice. ...