Show HN: Why write code if the LLM can just do the thing? (web app experiment)

Posted by samrolken 11/1/2025

Show HN: Why write code if the LLM can just do the thing? (web app experiment)(github.com)

I spent a few hours last weekend testing whether AI can replace code by executing directly. Built a contact manager where every HTTP request goes to an LLM with three tools: database (SQLite), webResponse (HTML/JSON/JS), and updateMemory (feedback). No routes, no controllers, no business logic. The AI designs schemas on first request, generates UIs from paths alone, and evolves based on natural language feedback. It works—forms submit, data persists, APIs return JSON—but it's catastrophically slow (30-60s per request), absurdly expensive ($0.05/request), and has zero UI consistency between requests. The capability exists; performance is the problem. When inference gets 10x faster, maybe the question shifts from "how do we generate better code?" to "why generate code at all?"

436 points | 324 commentspage 6

pscanf 11/1/2025|

Nice experiment!

I'm using a similar approach in an app I'm building. Seeing how well it works, I now really believe that in the coming years we'll see a lot of "just-in-time generation" for software.

If you haven't already, you should try using qwen-coder on Cerebras (or kimi-k2 on Groq). They are _really_ fast, and they might make the whole thing actually viable in terms of speed.

ilaksh 11/2/2025||

Will be interesting to see how fast inference ASICs, diffusion LLMs, architectural changes like IBM granite small (when is that coming to OpenRouter?) and slight compromises for pre-generation can speed this up.

Also I wonder if eventually you could go further and skip the LLM entirely and just train a game world frame generator on productivity software.

broast 11/1/2025||

Good work. I've been thinking about this for awhile and also experimenting with letting the LLM do all the work, backend logic plus generating the front-end and handle all front-end events. With tool use and agentic loops, I don't see any reason this can't work where it meets the latency needs (which hopefully could be improved over time).

causal 11/1/2025||

But you're still generating code to be rendered in the browser. Google is a few steps ahead of this: https://deepmind.google/discover/blog/genie-2-a-large-scale-...

thorax 11/2/2025||

I like the OP's idea and think it actually has some fun you applications. Especially with a little more narrowing of scope.

Similar fun concept as the cataclysm library for Python: https://github.com/Mattie/cataclysm

jes5199 11/1/2025||

huh okay, so, prediction: similar to how interpreted code eventually was given JIT so that it could be as fast as compiled code, eventually the LLMs will build libs of disposable helper functions as they work, which will look a lot like “writing code”. but we’ll stop thinking about it that way

mmaunder 11/1/2025||

This is brilliant. Really smart experiment, and a glimpse of what might - no what will be possible. Ignore the cynics. This is an absolutely brilliant thought experiment and conversation starter that lets us look ahead 10, 20, 50 years. This, IMHO, is the trajectory the Web is really on.

predkambrij 11/1/2025||

CSV is a lot lighter on tokens, compared to json, so it can go further, before a LLM gets exhausted.

finnborge 11/1/2025|

If you haven't already seen the DeepSeek OCR paper [1], images can be profoundly more token-efficient encodings of information than even CSVs!

[1]: https://github.com/deepseek-ai/DeepSeek-OCR/blob/main/DeepSe...

MangoCoffee 11/1/2025||

Here's why I don't get why people are badmouthing AI assist tools from Claude for Excel to Cursor to any new AI assist tool.

Why not try it out, and if it doesn't work for you or creates more work for you, then ditch it. All these AI assist tools are just tools.

tjr 11/1/2025||

Anecdotally, I've seen people do just that. Say, "I've tried it, it either didn't help me at all, or it didn't help me enough to be worth messing with."

But pretty consistently, such claims are met with accusations of not having tried it correctly, or not having tried it with the best/newest AI model, or not having tried it for long enough.

Thus, it seems that if you don't agree with maximum usage of AI, you must be wrong and/or stupid. I can understand that fostering feeling the need to criticize AI rather than just opt out.

MangoCoffee 11/1/2025|||

i get your point. i've mixed result with AI tool like Github copilot and Jetbrains Junie.

phyzome 11/1/2025|||

Yeah, this is my precise experience. No matter what I say, some AI booster will show up to argue that I didn't experience what I experienced.

(And if I enjoyed being gaslighted, I'd just be using the LLMs in the first place.)

Konnstann 11/1/2025||

The problem arises when there's outside pressure to use the tools, or now you're maintaining code written by someone else through the use of the tools, where it could have been good enough for them because they don't have to deal with downstream effects. At least that's been my negative experience with AI coding assistance. You could say "just get a new job" but unfortunately that's hard.

MangoCoffee 11/1/2025||

>You're maintaining code written by someone else through the use of these tools, where it could have been good enough for them.

I believe everyone has to deal with that, AI or not. There are bad human coders.

I've done integration for several years. There are integrations done with tools like Dell Boomi (no-code/low-code) that work but are hard to maintain, like you said. But what can you do? Your employer uses that tool to get it running until it can't anymore, as most no-code/low-code tools can get you to your goal most of the time. But when there's no "connector" or third-party connector that costs an arm and a leg, or hiring a Dell Boomi specialist to code that last mile, which will also cost an arm or a leg, then you turn to your own IT team to come up with a solution.

It's all part of IT life. When you're not the decision-maker, that's what you have to deal with. I'm not going to blame Dell Boomi for making my work extra hard or whatnot. It's just a tool they picked.

I am just saying that a tool is a tool. You can see many real life examples where you'll be pressured into using a tool and maintaining something created by such a tool, and not just in IT but in every field.

diwank 11/1/2025|

Just in time UI is incredibly promising direction. I don't expect (in the near term) that entire apps would do this but many small parts of them would really benefit. For instance, website/app tours could be just generated atop the existing ui.

More comments...