RAG is basically good old information retrieval with LLMs doing the querying. This can include vector search but it works without that as well. Treating vector search as magic pixie dust that makes search great without effort is not necessarily going to work that well. Also, it can add a lot of cost and complexity to the equation. And if not tuned properly, you don't necessarily get good results.
The key thing with RAG is to get the right information in the context with as few queries as possible. That requires good recall (ensuring that if it is there it can be found with a reasonable query) and precision (ensuring the best stuff is on top and minimizing false positives).
With search, and by extension RAG, the principle of shit in, shit out applies. Most of what search teams did before AI and RAG is still the best way to optimize the experience with RAG. And if you mess that up, search is not going to be working that well and no amount of AI can compensate for that or only at great cost in tokens and time. So, having an ETL pipeline to pre-process what you index, testing & benchmarking search quality, etc. are all helpful.
The good news is that you don't need that much skills with agentic coding to build something half decent for this. This code almost writes itself. And even a little bit of effort on extracting structure before indexing can make a big difference.
> RAG is basically good old information retrieval with LLMs doing the querying.
No - rag is doing search before you call the llm to give it context from some corpus like your helpdesk articles.
> With search, and by extension RAG, the principle of shit in, shit out applies
Similar to SEO on marketing pages, we started rewriting product docs around the idea that it will be consumed by a RAG. Mostly by putting a lot of focus on well structured headlines, thinking more carefully about technical terminology vs common human-language questions, occasionally using variations of keywords in the text, etc. This applies to pure LLM consumption too, not just hybrid search.
Once you start tracking what users are asking you learn to adapt the documentation around it. And LLMs can also suggest improvements by comparing questions vs search results vs LLM responses.