Your First RAG System
Stand up Postgres + pgvector, generate OpenAI embeddings, ingest a corpus, run naive retrieval, and ship a working chat-with-docs demo end-to-end.
Build production RAG systems — embeddings, vector search, chunking, and evaluation.
RAG is the most practical AI system pattern today. If you can build retrieval, you can build AI products.
Hands-on RAG pipeline from scratch. Postgres + pgvector, OpenAI embeddings, naive chunking. By the end you have a working demo.
Stand up Postgres + pgvector, generate OpenAI embeddings, ingest a corpus, run naive retrieval, and ship a working chat-with-docs demo end-to-end.
Embeddings, chunking, retrieval, generation — the four levers that decide whether your RAG works in production. Each one has tradeoffs and failure modes.
Embedding model tradeoffs (OpenAI vs BGE vs E5), cosine vs dot product, HNSW vs IVF index choice, dimensionality, and the ANN tuning that actually moves the needle in production.
Fixed-size vs recursive vs semantic chunking, overlap design, table and code preservation, header-aware splits, and the A/B benchmark methodology to pick a default that survives your corpus.
Hybrid retrieval — BM25 + dense fused via Reciprocal Rank Fusion — cross-encoder reranking, score floors, query rewriting, and the latency-budget tradeoffs every reranker buys you.
Context assembly under retrieval, citation injection, system-prompt design for grounded answers, streaming, and hallucination guards that don't kill answer quality.
Evaluation, advanced patterns, and deployment. Recall@k, hallucination detection, query routing, and the observability you need to keep RAG alive on-call.
Recall@k, MRR, RAGAS faithfulness / answer-relevancy / context-precision / context-recall, golden-set design, and eval-as-canary in CI so retrieval regressions get caught before users do.
Query expansion, multi-query, HyDE, multi-vector, ColBERT-style late interaction — plus the RAG security surface: prompt injection through documents, retrieval leakage, and access-control patterns.
Caching strategies (semantic + exact-match), cost attribution per query, monitoring (latency, hit rate, faithfulness drift), runbook design, and the observability stack that keeps RAG alive on-call.
Without the full system, you risk:
Retrieval-Augmented Generation (RAG) is an AI architecture that combines document retrieval with LLM generation to produce accurate, grounded responses. RAG systems embed documents into vectors, search for relevant context, and pass that context to an LLM for answer generation. Used by companies like Notion, Glean, and Microsoft Copilot to build AI products that leverage proprietary data.
RAG is the dominant pattern for building AI products over company data. At Notion, RAG powers AI search across millions of documents. Production RAG requires careful chunking strategies, hybrid retrieval, and evaluation pipelines — naive implementations produce hallucinations and miss critical context.
RAG retrieves relevant context at query time from external data. Fine-tuning bakes knowledge into model weights. RAG is better for frequently changing data; fine-tuning for stable domain expertise. Most production systems use both.
RAG augments prompts with retrieved context automatically. Prompt engineering crafts prompts manually. RAG scales to large knowledge bases; prompt engineering works for smaller, static contexts.
RAG uses vector similarity for retrieval. Knowledge graphs use structured relationships. Graph-RAG combines both approaches for better reasoning over complex, interconnected information.
RAG system design is the bridge into AI engineering. This skill proves you can build the retrieval layer that makes LLMs useful — the most in-demand AI capability in 2026.
RAG (Retrieval-Augmented Generation) retrieves relevant documents and feeds them to an LLM as context. This grounds the model response in actual data, reducing hallucinations and enabling AI over proprietary information.
RAG is more relevant than ever. As LLM context windows grow, RAG evolves but remains essential for cost-effective retrieval, citation grounding, and access control over sensitive documents.
A basic RAG prototype takes 1-2 days. Production RAG with proper chunking, hybrid retrieval, evaluation, and monitoring takes 4-8 weeks to build and tune.
RAG is better for dynamic, frequently changing data. Fine-tuning is better for stable domain expertise and style. Most production systems combine both — fine-tuning for behavior, RAG for knowledge.
Poor chunking that loses context, naive embedding that misses relevant documents, lack of evaluation metrics, and no hybrid retrieval. Production RAG requires systematic optimization of each component.
RAG is the bridge skill between data engineering and AI engineering. Building retrieval pipelines, embedding infrastructure, and evaluation systems are data engineering problems with AI applications.