Comment by repelsteeltje

I don't see how design plays a role. Imo first and foremost predictability/compatibility/stability isa QA problem. And I would not know where to start even if testing (ie avoiding regressions during development) were properly in place.

For plain old software development, supporting installed base was always far more difficult than designing and building new features. Doable, but hard.

With LLMs it's much harder. For instance, we built a transcript summarization service that customers were happy with. Then we improved the LLM, but we could not just yank the old LLM and replace it with the new version. Some customers would see the improvements, but others would complain that the new tone was ... just different.

I can't imagine how much more complicated it would be if the LLM was not under our control and had evolved to better help the customer.

But maybe I'm just misunderstanding what you're intending to build?