LangChain vs LlamaIndex for enterprise orchestration

Experience report: - LangChain: Huge ecosystem, chains and agents, great for tool calling. Can be verbose; careful abstraction selection helps. - LlamaIndex: Strong document loaders, indexes, observability plugins. Feels natural for RAG-first apps. - Both: Tracing, callbacks, support for many models/stores. What mattered: Clear boundaries (ingest, retrieve, generate), testability of each stage, and production-ready tracing. Verdict: If you are RAG-heavy with complex ingestion, LlamaIndex has an edge. For agentic flows and diverse tools, LangChain fits better. Many teams mix: LlamaIndex for data, LangChain for orchestration.