[coldtea]

>It largely works and it's a massive business success. This is the classic engineer asking the 'why this technology?' to what amounts to a business question.

Your counter argument would be valid for a 2000 or a 2020 business decision about some tech stack.

But the whole point of their product is that it supposedly nullifies such "business" concerns around the use of technology, by making it cheap and fast to build whatever you like automatically.

That they wont, or worse, couldn't, speaks against that.

[weakfish]

Yeah, this is what I’m trying to get at.

There’s two arguments in competition:

1. LLMs make it cheap (in the time sense) and easy to build

2. Rewrites and/or writing something in a native app or program is harder and more time consuming

I think I am willing to take it as an axiom that a native version of CC would be superior from a user perspective. Performance, etc.

I just don’t see how one can say that building things reliably good is easy now when the company providing these tools can’t even do it well.

[coldtea]

>2. Rewrites and/or writing something in a native app or program is harder and more time consuming

Why would it be harder and/or more time consuming rather than the opposite? It's like having full specs and a full test-suite to match against the result you want.

[munksbeer]

> I just don’t see how one can say that building things reliably good is easy now when the company providing these tools can’t even do it well.

What do you mean? Claude cli is wildly successful. Why do they need to re-write?

[pdimitar]

> I just don’t see how one can say that building things reliably good is easy now when the company providing these tools can’t even do it well.

I don't know how you can't see it, to me it's blindingly obvious: risk aversion.

Let's say the risk for a problem is 1%; hell, let's put it at 0.1% even. For a company at this scale even that amount of risk is too much.

I trust Opus/Fable to drive prod database migrations and backfills. I don't trust it with our financial ledger. I trust it with part of the infra. I don't trust it with backups. Etc.

You and others are arguing against a premise that nobody defended, namely "Claude can rewrite everything, for free and with zero mistakes". A bit of a straw man, don't you think?

And that's not even touching the fact that writing a GUI app is difficult for LLMs due to difficulties in it getting feedback and a "feel" whether it delivered what was asked (though I know people are working on it).

> I think I am willing to take it as an axiom that a native version of CC would be superior from a user perspective. Performance, etc.

How does that follow, and from where? I never once noticed any visual jank/lag in the TUI; not in iTerm2, not in Kitty, not in Alacritty, not in WezTerm and not in Ghostty. And even if we exclude those two, me and many other devs are quite fine with a TUI and don't miss a GUI program for everyday coding.

Not saying that our preference is superior -- but it'd be strange to blatantly claim: "for dev purposes, GUI > TUI/CLI".

[weakfish]

Going to give a short reply to one point because I’m about to go to sleep (I try to make an effort to be honest as to why I’m not fully engaging with the entire comment) but re: strawman, I don’t think so. When Dario Amodei is saying SWEs will be replaced soon [0], I think it follows that then he believes Claude can write a native app as well as a native app dev.

0 - https://finance.yahoo.com/news/anthropic-ceo-predicts-ai-mod...

[pdimitar]

CEOs love to promise the sky and the stars. Color me unimpressed.

Now whether they can do it -- that's a separate, and a much more interesting, discussion.

[weakfish]

Oh yeah, I mean I certainly think it’s a false premise. But it is a premise someone is giving.

[pdimitar]

> But the whole point of their product is that it supposedly nullifies such "business" concerns around the use of technology, by making it cheap and fast to build whatever you like automatically.

This is a spectrum, it's not just 0% vs 100%. Even Fable frakked up a few things really badly in my professional work (though to its credit after a very detailed 2h chat it self-corrected and fixed all the blunders).

I would also challenge "fast" -- Fable (and I assume Mythos) are wicked fast and efficient and even they can't compensate for f.ex. slow recompilations or test suite reruns or security scans, linters etc.

Reminder that the Bun's Zig-to-Rust rewrite took 11 days with dozens of agents working 24/7 and the author put the cost they'd pay (if they had to pay) at about $168k.

[hyperpape]

> $168k

Billions of dollars of annual revenue go through Claude Code, and the people who work on it must be a lot of millions in headcount.

The time matters a fair bit, it's probably time someone can't spend breaking things in the name of new features, but if rewriting the stack had even a tiny impact on retention or driving higher usage, it would pay back that $168k.

[sscaryterry]

If only paying the $168k was some sort of a guarantee. Vibing doesn't give you that.

You might get more maintainable code for $168k by hiring humans, but if its something bespoke it isn't going to get you far (or far quickly).

Vibing is straight out gambling right now, the thing is, I don't know who the house is any more.

[nomel]

It's going to take an order of magnitude longer though, delaying any of that revenue significantly. I'm sorry, but we're talking 11 days here. What does "maintainable" even mean with impossible time-scales like this now!?

[sscaryterry]

The new normal is there is no normal. No common sense, FOMO, YOLO, everything combined is what we're living right now :)

[nkrisc]

Perpetual complete rewrites. When there’s more bugs the LLM can fix, rewrite the whole codebase. Repeat ad infinitum.

[pdimitar]

True on the premise, remains to be seen if that's what's going to happen in practice.

In my work I have Fable/Opus add bespoke linters and tie them to verify/precommit tasks (including in CI) so nothing of the reworks and 15+ initiatives we have in flight ever regresses.

Some discipline will remove that worry of yours. It's not nice to immediately assume that the rewrite's orchestrator (Jarred) did not use discipline. He even outlined a few false starts.

[throwaway7783]

.. by hiring the right humans - which is not always a given

[pdimitar]

Even worse: it's much safer to assume you'll hire the wrong humans, most of the time.

[NDizzle]

The company I work for is about 15mm into what is effectively a rewrite. Just a lone data point…

[NuclearPM]

Millimeters?

[ak39]

I read "man months".

[ariwilson]

15 million dollars

[malkia]

15 million mollars :)

[pdimitar]

Yep, same thought. And it seems Anthropic agrees.

[mobelkh]

can't imagine rewriting a runtime to be easier than a coding harness

[usef-]

You might be surprised. Runtimes can be easier to test than UI for AI, and the bun rewrite was almost line-for-line translation, whereas CC likely uses many more libraries that cannot be ported directly.

The major open harnesses are in the ~800k lines of code size ( https://simonwillison.net/2026/Jul/15/grok-build/ ) and CC is the oldest and quite-likely largest judging by features.

[pdimitar]

It's really not about a PL runtime vs. an agent harness, it's about how spaghetti and complex the code is. I do get your point though.

[coldtea]

>Reminder that the Bun's Zig-to-Rust rewrite took 11 days with dozens of agents working 24/7 and the author put the cost they'd pay (if they had to pay) at about $168k.

For an entity like Anthropic that's not even the cost of a single developer for a year. It's closer to what they pay a chef on premises.

That the showstopper for a better Claude agent is that they'd need to pay $168k or event $1M or even $10M in costs, can't be used as an excuse.

[jbvlkt]

Lets see what happens in the future. From my experience cost of maintaining this amount of shitty code explodes pretty quickly. We will see in a few years if SW development in all phases using agents is that much automated and easy as people now predict.

[hluska]

Do you know their entire roadmap? If not, maybe different people prioritize things differently when they see their full strategic position.

[coldtea]

How is that relevant to my response?

The argument I responded to argued that cost might be the prohibiting factor. I'm saying that for them, the costs mentioned are negligible.

[pdimitar]

I didn't claim that the cost is the prohibiting factor at all. Obviously they gave Jarred free Fable access and to do as his pleases. The cost was an FYI tidbit and nothing more.

What I argued was that you seemed to have been arguing an extreme point i.e. LLMs can one-shot stuff in any PL and that it does not matter in what PL they'd rewrite Bun.

If I misunderstood -- my apologies.

[coldtea]

Well, I never said anything about one-shotting it.

What I said is, those AI companies push LLMs as the replacement of programmers, that can do everything code-wise, say their programmers "don't write code anymore" etc.

So how come they can't have the LLM write something better than "react for cli" for their flagship agent product?

[pdimitar]

I don't work for them and I don't know their priorities. I can only speculate they're not okay with it but no idea why exactly.

[TurdF3rguson]

It has to have been purely a marketing move. There's no other way that acquiring a software product for millions and then completely rewriting it makes any sense.

[pdimitar]

Maybe it's one of the cases when techies call the shots?

I can understand people being more sold on Rust compared to Zig -- there are legitimate differences on the memory safety front and I can see how people will prefer one or the other.

Plus I believe Jarred (Bun's main dev) went out of his way to explain why he chose Rust over Zig in his blog post.

Of course the marketing angle might indeed be the explanation; not arguing against that, I simply followed with interest and Jarred seemed very reasonable to me.

[TurdF3rguson]

The rewrite makes sense, it's all their dog food at that point. It's the acquisition that doesn't make sense. Why didn't Anthropic just rewrite it themselves?

[pdimitar]

Good question. I'd guess they didn't want community split?

[tonyhart7]

"Why didn't Anthropic just rewrite it themselves?"

they rewrite themselves, Bun team is under Antrophic umbrella

[shafyy]

> Reminder that the Bun's Zig-to-Rust rewrite took 11 days with dozens of agents working 24/7 and the author put the cost they'd pay (if they had to pay) at about $168k.

Does anybody really believe that it only took 11 days, one engineer and $168k in tokens?

[simonw]

It played out in public on the GitHub repository, so yes.

[pdimitar]

I know what Fable did for just 5x6h sessions, singular agent, for my professional work.

Jarred used many agents and they worked 24/7. It tracks for me.

So yes, I do believe it. What makes you skeptical?

[greenavocado]

100% believe it. I use multi agent orchestration within oh-my-pi and it can absolutely do targeted things like this.

[KronisLV]

> by making it cheap and fast to build whatever you like automatically.

Cheaper, but not free (if you don't buy into the marketing promises too much). The bigger the project, the bigger the cost, even with a discount.

At the same time, the early versions weren't very good and you can be sure that any rewrite will also need to be similarly iterated upon until it is also good enough and polished.

If you do that and don't spend enough effort on making it be something polished --> your competitors have a better product and you lose.

If you pause feature development to give enough effort to the initiative, you don't get to add new features quickly enough --> your competitors have a better product and you lose.

Maybe their priorities lay elsewhere, like how I've noticed that the desktop app version of Claude Code has gotten both faster (no 2-4 second lag when switching conversations), more stable and usable over time, to where I enjoy using the models because of it, not in spite of it (though not that they haven't had bumps along the way, like that one cache invalidation issue, or how people didn't like the auto accept timeout thing). I don't doubt that you can get pretty far with gradual patches and improvements, instead of only big rewrites.

Honestly it's really cool for me to see Kimi having their own CLI too, same with OpenCode, Pi, Hermes (well more of an agent than just a coding harness but you get the idea) - there's so many competing solutions out there, each good or bad in unique ways.

Just wish we'd see similarly many GUI solutions, for now OpenCode GUI seems like the one I've settled on (cross platform and supports most models), though it's not exactly ideal either (feels a bit barebones, especially in regards to sub-tasks and progress/plan tracking, even ZCode seems a bit better in that regard, it was actually surprisingly good after they pushed out some updates).

[arijun]

Can't have been that cheap if they thought buying Bun for an undisclosed amount of money was cheaper.

[tracerbulletx]

I don't think they bought them just for the claude-code gui harness as it is now. it's to have strategic control over some software runtime they can use to do other things related to verification, deployment, and end to end value delivery. Same reason other companies are buying up dev tools.

[arijun]

Yeah it was a little tongue-in-cheek--I think the estimate I saw was over $100M for bun, which would have been enough to pay Donald Knuth to rewrite Claude Code, let alone AI.

[vovavili]

I suspect it's at least partly akin to OpenAI buying uv where they did not want a startup with questionable profitability horizons that serves as a critical piece for their business to get suffocated when VCs come for their money back.

[madeofpalk]

How much extra money do you think they would make if Claude Code wasn’t JavaScript?

[piker]

Right now? Zero.

In 2 years? A well-engineered TUI could be the difference between the Blackberry and the iPhone for all we know.

[squidbeak]

Perhaps over those two years they'll reach the same conclusion and change the engineering?

[coldtea]

Perhaps by then it can be too little, too late, too?

[piker]

Perhaps.

[TurdF3rguson]

Claude is better at Javascript than those other languages though so maybe it would be worse in a better language.

[lacy_tinpot]

>making it cheap and fast to build whatever you like automatically

This can be true, while "nullifies such "business" concerns" can be false. Both are not dependent on each other.

Automation doesn't "nullify business concerns", it just changes them.

[harrisonjackson]

By the same argument, why does it matter from the technology stack side? It doesn't just nullify the business concerns - it largely nullifies the tech stack concerns. Your preference doesn't matter if you aren't touching the code and the product works for your user base.

[jstummbillig]

> But the whole point of their product is that it supposedly nullifies such "business" concerns around the use of technology, by making it cheap and fast to build whatever you like automatically.

Eventually? I am sure they would agree. Currently it's you (and lots of people like you) who are doing the supposing, not Anthropic.