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jiggawattsyesterday at 9:26 AM2 repliesview on HN

> while you could ask your LLM to do that you aren't going to run your bank on the result.

Why not?

I feel like we're entering a new era of prejudice against not a category of humans, but against non-human intelligences.

The design patterns for distributed and fault-tolerant systems are well-known and established in the industry. Both humans and AIs are familiar with them!

So if you sketch a design for the AI to follow, establish the rules in AGENTS.md, have a robust test suite, use a frontier model dialed up to eleven, etc... why not rely on the LLM output?

At the end of the day, humans are not without fault either.

I've been wading through some legacy "pre-AI" code recently and it has more bugs than a rainforest! Static fields used incorrectly, causing data races. Floating point types used for money amounts. JavaScript and SQL injection up the wazoo. Wildly unsafe password handling. So on, and so forth. This is the norm for most human-written software, not the exception.

As a proof-of-concept, I tried an AI rewrite of one such legacy app[1], and it is not bug free, but it notably has fewer bugs than the original. Different bugs, sure, and I'll have to iron them out after a round or two of UAT, but I'm honestly more confident with what I got from the chatbot than the code inherited from humans.

[1] Deals with money, but admittedly at a much lower level of risk and consequence than a banking app running on a mainframe.


Replies

CamouflagedKiwitoday at 4:07 PM

Because you know that the current one works. If you have a bank running on COBOL (or whatever), you've had that for 30+ years now, so while it might have bugs, you know what they are. You don't know what the LLM output is. Hence back to my original point: writing the code is not the hard bit. Making yourself (and your CEO etc) comfortable to put that into production is one of the hard bits.

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athanagor2today at 2:38 PM

How did you conduct this rewrite? Did you hand the AI some specs, some tests, the existing code?

I feel like AI has dramatically changed how complete rewrites can be considered, especially for long-lived, legacy projects.