r/LangChain • u/Sensitive-Parsnip-12 • 1d ago

Question | Help does anyone else feel like debugging multi step LLM apps turns into detective work pretty quickly?

/r/LLMDevs/comments/1w3hykr/does_anyone_else_feel_like_debugging_multi_step/
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u/Michael_Jeffords 1d ago

the detective part for me was not knowing which seat actually served the hop. once i logged model, provider, and cache hit or miss on every step, half the "bad prompt" mysteries were just a silent fallback.

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u/Sensitive-Parsnip-12 16h ago

what made you realize it was the fallback path and not actually the prompt? and before you started logging model/provider/cache per step, how were you usually trying to track that down?

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u/Michael_Jeffords 15h ago

same prompt giving two different answer shapes on the retry was the tell, and the generation receipt showed a different provider on that hop. before the per-step log i was just bisecting the prompt by hand and chasing ghosts that weren't in the text.

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u/Sensitive-Parsnip-12 14h ago

did you build anything around those per-step logs or are you just surfacing the model/ provider cache metadata in the tracing setup you already had

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u/Michael_Jeffords 12h ago

didn't build a separate thing. the tracer already wrote one row per hop, i just added model, provider, and cache hit as columns so a silent seat-change showed up in the same table i was already grepping.

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u/Sensitive-Parsnip-12 12h ago

makes sense the real fix was mostly making the execution context visible enough that the provider switch stopped looking like a prompt problem. appreciate you breaking that down.