Prevent AI Assistant From Using Outdated Documents

We're working on an internal AI assistant that helps our team answer questions using customer documents such as contracts, pricing rules, operating procedures, and approval policies. We have one specific issue we want to solve. Sometimes a customer uploads a newer version of a document, but the older version may still exist in the system for a period of time. For example: - A customer's old pricing policy says an approval limit is $25,000. - They upload a new version changing that limit to $15,000. - From that point forward, our AI assistant should only use the new version. The concern is that the AI could still find information from the old document and give an outdated answer, even if the answer looks correct and includes a source. We'd like someone to build a small standalone proof of concept showing a reliable way to prevent this. The solution should demonstrate that: - different customers' documents stay separate - newer versions can replace older versions - old versions can remain stored without being used in new answers - the AI only uses the current valid version - outdated documents cannot appear as sources - the system still behaves correctly if a document changes while an answer is being generated This does not need to connect to our existing systems. You can build and test everything independently using sample data. ### Deliverables We'd like to receive: - working source code - simple setup instructions - tests showing the old document is no longer used after a new version is published - a short explanation of how the approach works - brief notes on how the same idea could later be added to a production AI/RAG application Our current platform uses Python and PostgreSQL, so experience with Python, RAG systems, vector search, or AI document retrieval would be helpful. This is intended to be a small, focused task and should be suitable for someone experienced in this area to complete in a few hours. When applying, please briefly explain how you would make sure an AI system always uses the latest valid document when several versions may still exist.