Is 'Advanced RAG' Worth It? Measuring the ROI of Hybrid Search and Reranking
In AI engineering, there’s a pattern I call “ Magpie Architecture. ” An engineer spots a shiny technique—HyDE, knowledge graphs, cross-encoder reranking—and the next instinct is to add it straight into production. The argument is always the same: “It will make the answers better.” Sometimes it will. But in a business context, “better” has a price tag. Every added layer in a Retrieval-Augmented Generation (RAG) stack typically increases: Latency (how long users wait), Compute cost (your infrastructure bill), and Operational complexity (more parts to own, test, and maintain). So as a manager or architect, the real question becomes: Is the marginal gain in quality worth the marginal increase in cost? Here’s a practical way to stop guessing and start measuring ROI using Databricks Vector Search and MLflow evaluation .