Ask HN: What was your "oh shit" moment with GenAI?

I had access to a repo (from a closed startup) with 800K lines of python & C code, written from the 90s to today. They had some very interesting approach to a specific chemistry problem. 20-30 years of work of several persons.

But God, I could not understand the code, and I could not easily make it work with modern technologies (GPU etc).

So I used Claude and Gemini to reverse engineer the codebase, extract the core ideas, and rewrite it from scratch with modern frameworks (with guidance from the original authors)

It took me only 10 days to have a functioning equivalent, in 10K lines of code (using many libraries that did not exist in the 90s and 00s), which I find much easier to understand, even though I wrote none of it myself.

10 days to rewrite 20-30 year of a few persons. That was quite scary.

I did not yet have a positive "oh shit" moment, but when the corporate manager types that could not deliver a "Hello world" if their live would depend on and would have had a sour look on their face when asked to pay license fees for a proper IDE a 10 to 15 years ago started pushing it hard, way before any but the resume-driven engineers: that has flipped a bit in me.

They've been coming faster and faster for me. First I was blown away by GPT2, specifically the fake news article about talking unicorns. Just stringing together a few sentences while maintaining logical coherence was very impressive at the time.

Then it was models like Minerva that could actually solve math problems, and the discovery that LLMs were one-shot learners and could write code.

After that, the improvement felt pretty steady, with IMO gold feeling like a watershed moment.

And recently OpenAI's solution to the planar unit distance problem is starting to actually freak me out a bit.

I've been using Gemini for that - it feels like it practically thinks in images (or "possesses impressive visual intelligence," as Google execs would put it).

Coding up a decent performing basic 3D finite element solver from scratch in C++. Still needed to know what I was doing but it’s a non trivial problem.

I still couldn’t get it to do more advanced stuff.