Prod Level RAG Applications

Hi everyone, I have been learning Rag for months and I have created some question-answering applications using LangChain to add to my resume. But I am wondering in real life, in production level rag applications, what is the difference from my local simple rag project? Which vectorstore do you use for your project, or embedding model? open source or api?

What are the biggest differences between production-level RAG applications and simple RAG projects on github? Are your documents usually pdf or csv?

Thank you.