· 9 min read
Index Freshness and Drift: Why a Working RAG System Quietly Goes Wrong
A RAG system that works today degrades quietly as its documents change. There are two kinds of drift: the easy one, where the questions start looking different, and the nasty one, where the questions look identical but the right answer changed underneath. The fix is re-checking on a schedule against a baseline, and never auto-rebuilding when the alarm fires, because half the time it is a data-plumbing break, not a real change.