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I wish your recent interview had pushed much harder on this. It came across as politely not wanting to bring up how poorly this really went, even for what the e

by tyre 9mo ago

I wish your recent interview had pushed much harder on this. It came across as politely not wanting to bring up how poorly this really went, even for what the engineer intended. They were making claims without the level of rigor to back them up. There was an opportunity to learn some difficult lessons, but—and I don’t think this was your intention—it came across to me as kind of access journalism; not wanting to step on toes while they get their marketing in.

blibble 9mo ago
pushing would definitely stop the supply of interviews/freebies/speaking engagements
simonw 9mo ago
I just don't think that's the case. The claims they made really weren't that extreme. In the blog post they said: > To test this system, we pointed it at an ambitious goal: building a web browser from scratch. The agents ran for close to a week, writing over 1 million lines of code across 1,000 files. You can explore the source code on GitHub. > Despite the codebase size, new agents can still understand it and make meaningful progress. Hundreds of workers run concurrently, pushing to the same branch with minimal conflicts. That's all true. On Twitter their CEO said: > We built a browser with GPT-5.2 in Cursor. It ran uninterrupted for one week. > It's 3M+ lines of code across thousands of files. The rendering engine is from-scratch in Rust with HTML parsing, CSS cascade, layout, text shaping, paint, and a custom JS VM. > It kind of works! It still has issues and is of course very far from Webkit/Chromium parity, but we were astonished that simple websites render quickly and largely correctly. That's mostly accurate too, especially the "it kind of works" bit. You can take exception to "from-scratch" claim if you like. It's a tweet, the lack of nuance isn't particularly surprising. In the overall genre of CEO's over-hyping their company's achievements this is a pretty weak example. I think the people making out that Cursor massively and dishonestly over-hyped this are arguing with a straw man version of what the company representatives actually said.
- mikkupikku 9mo ago
  > That's mostly accurate too, especially the "it kind of works" bit. You can take exception to "from-scratch" claim if you like. It's a tweet, the lack of nuance isn't particularly surprising. > In the overall genre of CEO's over-hyping their company's achievements this is a pretty weak example I kind of agree, but kind of not. The tweet isn't too bad when read from an experienced engineer perspective, but if we're being real then the target audience was probably meant to be technically clueless investors who don't and can't understand the nuance.
- mjr00 9mo ago
  What people take issue with is the claim that agents built a web browser "from scratch" only to find by looking deeper that they were using Servo, WGPU, Taffy, winit, and other libraries which do most of the heavy lifting. It's like claiming "my dog filed my taxes for me!" when in reality everything was filled out in TurboTax and your dog clicked the final submit button. Technically true, but clearly disingenuous. I'm not saying an LLM using existing libraries is a bad thing--in fact I'd consider an LLM which didn't pull in a bunch of existing libraries for the prompt "build a web browser" to be behaving incorrectly--but the CEO is misrepresenting what happened here.
  - simonw 9mo ago
    I agree that "from scratch" is a misrepresentation. But it was accompanied by a link to the GitHub repo, so you can hardly claim that they were deliberately hiding the truth.
    - mjr00 9mo ago
      > But it was accompanied by a link to the GitHub repo, so you can hardly claim that they were deliberately hiding the truth. Well, yes and no; we live in an era where people consume headlines, not articles, and certainly not links to Github repositories in articles. If VCs and other CEOs read the headline "Cursor Agents Autonomously Create Web Browser From Scratch" on LinkedIn, the project has served its purpose and it really doesn't matter if the code compiles or not.
moomoo11 9mo ago
Why would he push back? His whole schtick is to sell only AI hype. He’s not going to hurt his revenue.
- square_usual 9mo ago
  That's a great way to tell on yourself that you've never read Simon's work.
  - blibble 9mo ago
    the bare minimum of criticism to allow independence to be claimed?
  - GoatInGrey 9mo ago
    On the contrary, we get to read hundreds of his comments explaining how the LLM in anecdote X didn't fail, it was the developer's fault and they should know better than to blame the LLM. I only know this because on occasion I'll notice there was a comment from them (I only check the name of the user if it's a hot take) and I ctrl-F their username to see 20-70 matches on the same thread. Exactly 0 of those comments present the idea that LLMs are seriously flawed in programming environments regardless of who's in the driver seat. It always goes back to operator error and "just you watch, in the next 3 months or years...". I dunno, I manage LLM implementation consulting teams and I will tell you to your face that LLMs are unequivocally shit for the majority of use cases. It's not hard to directly criticize the tech without hiding behind deflections or euphemisms.
    - simonw 9mo ago
      > Exactly 0 of those comments present the idea that LLMs are seriously flawed in programming environments regardless of who's in the driver seat. Why would I say that when I very genuinely believe the opposite? LLMs are flawed in programming environments if driven by people who don't know how to use them effectively. Learning to use them effectively is unintuitive and difficult, as I'm sure you've seen yourself. So I try to help people learn how to use them, through articles like https://simonwillison.net/2025/Mar/11/using-llms-for-code/ https://simonwillison.net/2025/Mar/11/using-llms-for-code/ and comments like this one: https://news.ycombinator.com/item?id=46765460#46765940 https://news.ycombinator.com/item?id=46765460#46765940 (I don't ever say variants of "just you watch, in the next 3 months or years..." though, I think predicting future improvements is pointless when we can be focusing on what the models we have right now can do.)
well_ackshually 9mo ago
The person you're responding to isn't a journalist, they're a mouthpiece. Pushing means they don't get these interviews anymore. The quality of whatever they put out as a result of it is yours to take into consideration.

by tyre 9mo ago

blibble 9mo ago

pushing would definitely stop the supply of interviews/freebies/speaking engagements

simonw 9mo ago

I just don't think that's the case. The claims they made really weren't that extreme. In the blog post they said: > To test this system, we pointed it at an ambitious goal: building a web browser from scratch. The agents ran for close to a week, writing over 1 million lines of code across 1,000 files. You can explore the source code on GitHub. > Despite the codebase size, new agents can still understand it and make meaningful progress. Hundreds of workers run concurrently, pushing to the same branch with minimal conflicts. That's all true. On Twitter their CEO said: > We built a browser with GPT-5.2 in Cursor. It ran uninterrupted for one week. > It's 3M+ lines of code across thousands of files. The rendering engine is from-scratch in Rust with HTML parsing, CSS cascade, layout, text shaping, paint, and a custom JS VM. > It kind of works! It still has issues and is of course very far from Webkit/Chromium parity, but we were astonished that simple websites render quickly and largely correctly. That's mostly accurate too, especially the "it kind of works" bit. You can take exception to "from-scratch" claim if you like. It's a tweet, the lack of nuance isn't particularly surprising. In the overall genre of CEO's over-hyping their company's achievements this is a pretty weak example. I think the people making out that Cursor massively and dishonestly over-hyped this are arguing with a straw man version of what the company representatives actually said.

mikkupikku 9mo ago
> That's mostly accurate too, especially the "it kind of works" bit. You can take exception to "from-scratch" claim if you like. It's a tweet, the lack of nuance isn't particularly surprising. > In the overall genre of CEO's over-hyping their company's achievements this is a pretty weak example I kind of agree, but kind of not. The tweet isn't too bad when read from an experienced engineer perspective, but if we're being real then the target audience was probably meant to be technically clueless investors who don't and can't understand the nuance.
mjr00 9mo ago
What people take issue with is the claim that agents built a web browser "from scratch" only to find by looking deeper that they were using Servo, WGPU, Taffy, winit, and other libraries which do most of the heavy lifting. It's like claiming "my dog filed my taxes for me!" when in reality everything was filled out in TurboTax and your dog clicked the final submit button. Technically true, but clearly disingenuous. I'm not saying an LLM using existing libraries is a bad thing--in fact I'd consider an LLM which didn't pull in a bunch of existing libraries for the prompt "build a web browser" to be behaving incorrectly--but the CEO is misrepresenting what happened here.
- simonw 9mo ago
  I agree that "from scratch" is a misrepresentation. But it was accompanied by a link to the GitHub repo, so you can hardly claim that they were deliberately hiding the truth.
  - mjr00 9mo ago
    > But it was accompanied by a link to the GitHub repo, so you can hardly claim that they were deliberately hiding the truth. Well, yes and no; we live in an era where people consume headlines, not articles, and certainly not links to Github repositories in articles. If VCs and other CEOs read the headline "Cursor Agents Autonomously Create Web Browser From Scratch" on LinkedIn, the project has served its purpose and it really doesn't matter if the code compiles or not.

moomoo11 9mo ago

Why would he push back? His whole schtick is to sell only AI hype. He’s not going to hurt his revenue.

square_usual 9mo ago
That's a great way to tell on yourself that you've never read Simon's work.
- blibble 9mo ago
  the bare minimum of criticism to allow independence to be claimed?
- GoatInGrey 9mo ago
  On the contrary, we get to read hundreds of his comments explaining how the LLM in anecdote X didn't fail, it was the developer's fault and they should know better than to blame the LLM. I only know this because on occasion I'll notice there was a comment from them (I only check the name of the user if it's a hot take) and I ctrl-F their username to see 20-70 matches on the same thread. Exactly 0 of those comments present the idea that LLMs are seriously flawed in programming environments regardless of who's in the driver seat. It always goes back to operator error and "just you watch, in the next 3 months or years...". I dunno, I manage LLM implementation consulting teams and I will tell you to your face that LLMs are unequivocally shit for the majority of use cases. It's not hard to directly criticize the tech without hiding behind deflections or euphemisms.
  - simonw 9mo ago
    > Exactly 0 of those comments present the idea that LLMs are seriously flawed in programming environments regardless of who's in the driver seat. Why would I say that when I very genuinely believe the opposite? LLMs are flawed in programming environments if driven by people who don't know how to use them effectively. Learning to use them effectively is unintuitive and difficult, as I'm sure you've seen yourself. So I try to help people learn how to use them, through articles like https://simonwillison.net/2025/Mar/11/using-llms-for-code/ https://simonwillison.net/2025/Mar/11/using-llms-for-code/ and comments like this one: https://news.ycombinator.com/item?id=46765460#46765940 https://news.ycombinator.com/item?id=46765460#46765940 (I don't ever say variants of "just you watch, in the next 3 months or years..." though, I think predicting future improvements is pointless when we can be focusing on what the models we have right now can do.)

well_ackshually 9mo ago

The person you're responding to isn't a journalist, they're a mouthpiece. Pushing means they don't get these interviews anymore. The quality of whatever they put out as a result of it is yours to take into consideration.