Comment by alzoid | Hacker News Reader

Comment by alzoid | Hacker News Reader

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I asked Claude to add a debug endpoint to my hardware device that just gave memory information. It wrote 2600 lines of C that gave information about every single aspect of the system. On the one hand kind of cool. It looked at the MQTT code and the update code, the platform (esp) and generated all kinds of code. It recommended platform settings that could enable more detailed information that checked out when I looked at the docs. I ran it and it worked. On the other hand, most of the code was just duplicated over and over again ex: 3 different endpoints that gave overlapping information. About half of the code generated fake data rather than actually do anything with the system.

I rolled back and re-prompted and got something that looked good and worked. The LLMs are magic when they work well but they can throw a wrench into your system that will cost you more if you don't catch it.

I also just had a 'senior' developer tell me that a feature in one of our platforms was deprecated. This was after I saw their code which did some wonky hacky like stuff to achieve something simple. I checked the docs and said feature (URL Rewriting) was obviously not deprecated. When I asked how they knew it was deprecated they said Chat GPT told them. So now they are fixing the fix chat gpt provided.

> About half of the code generated fake data rather than actually do anything with the system.

All the time

    // fake data. in production this would be real data
    ... proceeds to write sometimes hundreds of lines
    of code to provide fake data

"hey claude, please remove the fake data and use the real data"

"sure thing, I'll add logic to check if the real data exists and only use the fake data as a fallback in case the real data doesn't exist"

I will also add checks to make sure the data that I get is there even though I checked 8 times already and provide loads of logging statements and error handling. Then I will go to every client that calls this API and add the same checks and error handling with the same messaging. Oh also with all those checks I'm just going to swallow the error at the entry point so you don't even know it happened at runtime unless you check the logs. That will be $1.25 please.

This comment captures exactly what aggravates me about CC / other agents in a way that I wasn't sure how to express before. Thanks!

Claude (possible all LLMs, but I mostly use Claude) LOVES this pattern for some reason. "If <thing> fails/does not exist I'll just silently return a placeholder, that way things break silently and you'll tear your hair out debugging it later!" Thanks Claude

Optimizing for engagement? You will use Claude again for the debugging...

Hah I also happened to use Claude recently to write basic MQTT code to expose some data on a couple Orange Pis I wanted to view in Home Assistant. And it one-shot this super cool mini Python MQTT client I could drop wherever I needed it which was amazing having never worked with MQTT in Python before.

I made some charts/dashboards in HA and was watching it in the background for a few minutes and then realized that none of the data was changing, at all.

So I went and looked at the code and the entire block that was supposed to pull the data from the device was just a stub generating test data based on my exact mock up of what I wanted the data it generated to look like.

Claude was like, “That’s exactly right, it’s a stub so you can replace it with the real data easily, let me know if you need help with that!” And to its credit, it did fix it to use actual data but I re-read my original prompt was somewhat baffling to think it could have been interpreted as wanting fake data given I explicitly asked it to use real data from the device.

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