# RAG optimisation + Reranking Day 2 Lab

> In this lab, Zach focuses on re-ranking and working with an external worker process, which are crucial for optimizing the retrieval system. He implements metadata filtering and re-ranking to improve query results, ensuring that he accurately classifies document types and determines the optimal numb…

- Web page: https://www.dataexpert.io/lesson/rag-optimisation-reranking-day2-lab-oct2025-p737-l1574
- Program: [AIExpert](https://www.dataexpert.io/program/ai-expert)
- Module: Week 2: Advanced RAG, Reranking & Dev Workflow
- Access: Requires enrollment in AIExpert
- Length: 1 h 18 min video
- Skills: SQL, Python, NLP
- Academy: DataExpert.io Academy

## About this lesson

In this lab, Zach focuses on re-ranking and working with an external worker process, which are crucial for optimizing the retrieval system. He implements metadata filtering and re-ranking to improve query results, ensuring that he accurately classifies document types and determines the optimal number of documents to retrieve. He demonstrates how to set up a PubNub channel for asynchronous processing, allowing him to handle longer tasks without timing out.

## Navigation

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