by rstuart4133 | 2025-07-17 22:56:50+00:00
> But I think we've reached the point where such posts (both positive and negative) are _completely useless_, unless they're accompanied with a careful summary of at least ...

I use Claude many times a day, I ask it and Gemini to generate code most days. Yet I fall into the "I've never included a line of code generated by an LLM in committed code" category. I haven't got a precise answer for why that is so. All I can come up with is the code generated lacks the depth of insight needed to write a succinct, fast, clear solution to the problem someone can easily understand in in 2 years time.

Perhaps the best illustration of this is someone proudly proclaimed to be they committed 25k lines in a week, with the help of AI. In my world, this sounds like they are claiming they have a way of turning the sea into ginger beer. Gaining the depth of knowledge required to change 25k lines of well written code would take me more than a week of reading. Writing that much in a week is a fantasy. So I asked them to show me the diff.

To my surprise, a quick scan of the diff revealed what the change did. It took me about 15 minutes to understand most of it. That's the good news.

The bad news it that 25k lines added 6 fields to a database. 2/3's were unit tests, perhaps 2/3's of the remainder was comments (maybe more). The comments were glorious in their length and precision, littered with ASCII art tables showing many rows in the table.

Comments in particular are a delicate art. They are rarely maintained, so they can bit rot in downright misleading babble after a few changes. But the insight they provide into what author was thinking, and in particular the invariants he had in mind can save hours of divining it from the code. Ideally they concisely explain only the obscure bits you can't easily see from the code itself. Anything more becomes technical debt.

Quoting Woodrow Wilson on the amount of time he spent preparing speeches:

“That depends on the length of the speech,” answered the President. “If it is a ten-minute speech it takes me all of two weeks to prepare it; if it is a half-hour speech it takes me a week; if I can talk as long as I want to it requires no preparation at all. I am ready now.”

Which is a round about way of saying I suspect the usefulness of LLM generated code depends more on how often a human is likely to read it, than of any of the things you listed. If it is write once, and the requirement is it works for most people in the common cases, LLM generated code is probably the way to go.

I used PayPal's KYC web interface the other day. It looked beautiful, completely inline with the rest of PayPal's styling. But sadly I could not complete it because of bugs. The server refused to accept one page, it just returned to the same page with no error messages. No biggie, I phoned support (several times, because they also could not get past the same bug), and after 4 hours on the phone the job was done. I'm sure the bug will be fixed a new contractor. He spend an few hours on it, getting an LLM to write a new version, throwing the old code away, just as his predecessor did. He will say the LLM provided a huge productivity boost, and PayPal will be happy because he cost them so little. It will be the ideal application for an LLM - got the job done quickly, and no one will read the code again.

I later discovered there was a link on the page that allowed me to skip past the problematic page, so I could at least enter the rest of the information. It was in a thing that looked confusingly like a "menu bar" on the left, although there was no visual hit any of the items in the menu were clickable. I clicked on most of them anyway, but they did nothing. While on hold for phone support, I started reading the HTML and found one was a link. It was a bit embarrassing to admit to the help person I hadn't clicked that one. It sped the process up somewhat. As I said, the page did look very nice to the eye, probably partially because of the lack of clutter created by visual hints on what was clickable.

[0] https://quoteinvestigator.com/2012/04/28/shorter-letter/