LeetLLM
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Intermediate13 lessons

RAG and Search Systems

Learn document ingestion, retrieval, reranking, evaluation, and secure enterprise RAG as one coherent path.

Builders working on search, support bots, internal knowledge assistants, and document QA.

You can design a retrieval pipeline, debug faithfulness failures, and choose vector, lexical, and graph retrieval pieces deliberately.

  1. 1File Ingestion for AITurn PDFs, scans, HTML, and Markdown into faithful evidence records with provenance and quality checks before retrieval.Core LLM FoundationsMedium12 min
  2. 2Chunking StrategiesTurn clean documents into retrieval units that preserve answers, citations, and measurable search quality.Core LLM FoundationsMedium13 min
  3. 3Core Retrieval AlgorithmsBuild and evaluate the evidence-selection stage of a technical-docs assistant with BM25, dense similarity, rank fusion, reranking, and approximate search audits.ML Algorithms & EvaluationMedium16 min
  4. 4Sentence Embeddings & Contrastive LossLearn how contrastive losses train sentence embeddings, why hard negatives matter, and how retrieval systems combine bi-encoders, rerankers, and dimension tradeoffs.Transformer Deep DivesHard38 min
  5. 5Embedding Similarity & QuantizationLearn vector scoring contracts, evaluate Matryoshka widths, and measure scalar, product, and binary quantization before deploying compressed retrieval.Transformer Deep DivesHard39 min
  6. 6Production RAG PipelinesDesign a secure, traceable RAG service around versioned policy evidence, grounded answers, abstention, release gates, and latency budgets.Applied LLM EngineeringMedium17 min
  7. 7Hybrid Search: Dense + SparseUpgrade a permission-safe RAG retriever with BM25, semantic scores, rank fusion, and recall gates for exact codes and paraphrased policy questions.Applied LLM EngineeringMedium17 min
  8. 8Reranking and Cross-Encoders for RAGTurn a permission-safe hybrid candidate list into precise context using cross-encoder reasoning, ordering metrics, latency gates, and traceable evidence selection.Applied LLM EngineeringMedium14 min
  9. 9RAG Evaluation for Reliable AnswersEvaluate a permission-safe RAG answer trace with context, claim, citation, failure-attribution, and release gates before automating softer judgments.Applied LLM EngineeringMedium15 min
  10. 10Hallucination Detection & MitigationBuild a claim-level grounding gate for incident updates that verifies evidence, catches confident fabrication, abstains safely, and records release traces.Applied LLM EngineeringMedium15 min
  11. 11Vector DB Internals: HNSW & IVFLearn how approximate nearest neighbor indexes use HNSW, IVF, and Product Quantization to balance speed, recall, and memory in production vector databases.Advanced Agents & RetrievalHard37 min
  12. 12GraphRAG & Knowledge GraphsLearn how GraphRAG uses entity graphs, hierarchical community reports, and embeddings to retrieve evidence for relationship-heavy and corpus-level questions.Advanced Agents & RetrievalHard37 min
  13. 13RAG Security & Access ControlLearn how document ACLs, tenant isolation, retrieval-time authorization, output checks, and audit logs reduce private-data leakage risk in enterprise RAG.Advanced Agents & RetrievalHard38 min