RAG Interview Questions #21 - The GraphRAG Scaling Trap

The hidden trap where appending documents to a knowledge graph destroys your deduplication, and why senior engineers trade pure LLMs for a hybrid, tiered pipeline.

You’re in a Senior ML Engineer interview at Google and the interviewer asks:

“Your GraphRAG pipeline uses an LLM to extract entity-relationship triplets. It’s flawless in the demo. Now you’re ingesting 50K docs a week and your indexing bill is on fire. What did you trade away when you picked LLM extraction?”

Don’t say: “LLMs are more accurate than rule-ba…