[michaelschiff]

Hey, Michael here, CTO of Arize and minor contributor to Phoenix.

The ability to trace a piece of software is a night and day difference for understanding. Once you know it's possible to have this level of visibility into what your code is doing, its impossible to go back. Im really excited to see what people learn by applying Phoenix Traces to their applications.

I've spent ton of time debating the data model of the span information we collect, as well as many different instrumentation options. We started with LlamaIndex and LangChain callback systems as the hook for instrumentation, since those frameworks are a common way for developers to get started with LLMs. We will add support for custom instrumentation, allowing users to manage the creation of spans themselves and avoid framework lock-in. When it comes to custom instrumentation, Im curious where the community lies - are people planning to use OTEL for this, or is the expectation that LLM spans are different enough that they warrant a different approach?