Building WeaveLLM: Why .NET Deserves a Better LangChain Tags: dotnet, ai, csharp, llm Cover image: architecture diagram of WeaveLLM pipeline Introduction Here's a thing I keep running into: .NET developers building serious AI features, and the ecosystem basically telling them to just use Python. LangChain, LlamaIndex, DSPy — every major orchestration framework is Python-first. .NET is an afterthought, if it shows up at all. But C# developers aren't waiting around. They're shipping customer support bots, RAG pipelines, code-review agents — right now, in production. They're just doing it by calling OpenAI's REST API by hand, copy-pasting retry logic into every service class, and hoping nothing throws in an async chain at 2 AM. LangChain does have a .NET port. I've used it. It's incomplete, the types don't map cleanly to .NET idioms, and it leans on exceptions as its main error-handling strategy — which is genuinely painful to compose in async code.…