Story

I'm tasked with building a private AI assistant for a corpus of 10 million text documents (living in PostgreSQL). The goal is semantic search and chat, with a requirement for regular incremental updates.

I'm trying to decide between:

Bleeding edge: Implementing something like LightRAG or GraphRAG.

Proven stack: Standard Hybrid Search (Weaviate/Elastic + Reranking) orchestrated by tools like Dify.

For those who have built RAG at this scale:

What is your preferred stack for 2025?

Is the complexity of Graph/LightRAG worth it over standard chunking/retrieval for this volume?

How do you handle maintenance and updates efficiently?

Looking for architectural advice and war stories.