I spent the last three months building a production LLM app. I tried every major observability tool. None of them fit perfectly — so I built my own. Here's my honest take on each one. LangSmith What it gets right: Deep LangChain integration. If you're all-in on LangGraph, it's seamless. What it gets wrong: Everything else. Pricing is punitive.$39/seat/month — before you log a single trace. A t