That's all true, but sometimes things break because some package is bumped. I'd still like to know if my app is basically broken if an LLM has changed somehow.

That's all true, but sometimes things break because some package is bumped. I'd still like to know if my app is basically broken if an LLM has changed somehow. You are right that fine tuning would probably help to minimize the risks, but it probably never can be zero. New tests will also be needed when customers find new edge cases that break our assumptions. Testing LLM prompts is a new paradigm that we'll have to learn to deal with.