Beyond ChatGPT Wrappers: Building a Real Semantic Search API with ASP.NET Core and OpenAI Embeddings

Most developers jump straight to chat completions when they think "AI + backend." But the feature that's quietly changing how products work — semantic search — is more powerful, cheaper, and honestly more fun to build. The Problem with Keyword Search Imagine you're building a knowledge base for a SaaS product. A user types: "my account got locked" . Your keyword search returns nothing because your docs say "authentication failure" and "access denied." Same meaning. Zero matches. This is the gap