LLMsArchitectureBackendRAGAI

Implementing RAG Systems: From Prototype to Production

A comprehensive guide to building Retrieval-Augmented Generation systems. Covers chunking strategies, embedding models, vector databases, reranking, evaluation, and production hardening.

Alex Chen
18 min read

Implementing RAG Systems: From Prototype to Production

RAG combines the knowledge of LLMs with your private data. Here's how to build it right.

Architecture Overview

User Query → Embedding → Vector Search → Rerank → Context → LLM → Answer

Chunking Strategies

Fixed-Size with Overlap

Semantic Chunking

Split on semantic boundaries (headings, paragraphs).

Embedding Models

| Model | Dimensions | Use Case | |-------|------------|----------| | text-embedding-3-small | 1536 | General purpose | | text-embedding-3-large | 3072 | High accuracy | | bge-large-en-v1.5 | 1024 | Open source, strong |

Vector Database Comparison

  • pgvector — PostgreSQL extension, simple ops
  • Pinecone — Managed, serverless
  • Weaviate — Graph + vector, flexible
  • Qdrant — Rust-based, fast, filtering

Reranking

Evaluation Framework

Production Hardening

  • Circuit breakers for LLM calls
  • Request/response logging for debugging
  • Cost tracking per query
  • A/B testing framework
  • Gradual rollout with feature flags

Conclusion

RAG is more than vector search. Production systems need evaluation, monitoring, and iterative improvement. Start with a solid foundation, then optimize each component.

Share: