Documentation search: When your Rails app needs which approach

The article compares four approaches to building documentation search in a Rails app—from traditional Postgres full-text search with AI summarization to vector databases and RAG pipelines. It argues that developers often over-engineer search by defaulting to embeddings and agentic loops when simpler, proven tools like Postgres work well for typical scales. Each approach is evaluated by code complexity, cost per query, and latency using a realistic 5,000 Ruby gem documentation site.