Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Opus 4.5 is not the normal AI agent experience that I have had thus far

burkeholland.github.io

Post reply on HN
Print view View original

351–360 of 1001 posts

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#351

Post by throwaway173738 »

whatever1 wrote: post #323
multisport wrote: post #320

What bothers me about posts like this is: mid-level engineers are not tasked with atomic, greenfield projects. If all an engineer did all day was build apps from scratch, with no expectation that others may come along and extend, build on top of, or depend on, then sure, Opus 4.5 could replace them. The hard thing about engineering is not "building a thing that works", its building it the right way, in an easily unde…

Their thesis is that code quality does not matter as it is now a cheap commodity. As long as it passes the tests today it's great. If we need to refactor the whole goddamn app tomorrow, no problem, we will just pay up the credits and do it in a few hours.

It matters for all the things you’d be able to justify paying a programmer for. What’s about to change is that there will be tons of these little one-off projects that previously nobody could justify paying $150/hr for. A mass democratization of software development. We’ve yet to see what that really looks like.

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#352

Post by babelfish »

estimator7292 wrote: post #345
whatever1 wrote: post #323

Earlier quoted context omitted.

Their thesis is that code quality does not matter as it is now a cheap commodity. As long as it passes the tests today it's great. If we need to refactor the whole goddamn app tomorrow, no problem, we will just pay up the credits and do it in a few hours.

The fundamental assumption is completely wrong. Code is not a cheap commodity. It is in fact so disastrously expensive that the entire US economy is about to implode while we're unbolting jet engines from old planes to fire up in the parking lots of datacenters for electricity.

[citation needed]

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#353

Post by Hammershaft »

jcmfernandes wrote: post #59

To the author: you wrote those apps. Not like you used to, but you wrote them. IMO, our jobs are safe. It's our ways of working that are changing. Rapidly.

SWE jobs are in fact, not safe, if vaguely defined specifications can be translated into functioning applications. I don't think agents are good enough to do that in larger applications yet, but it is something to consider.

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#354

Post by _pdp_ »

YEP

Things are changing. Now everyone can build bespoke apps. Are these apps pushing the limits of technology? No! But they work for the very narrow and specific domain they where designed. And yes they do not scale and have as much bugs as your personal shell scripts. But they work.

But let's not compare these with something more advance - at least not yet. Maybe by end of this year?

We switched from Sonnet 4.5 to Opus 4.5 as our default coding agent recently and we pay the price for the switch (3x the cost) but as the OP said, it is quite frankly amazing. It does a pretty good job, especially, especially when your code and project is structured in a such a way that it helps the agent perform well. Anthropic released an entire video on the subject recently which aligns with my own observations as well.

Where it fails hard is in the more subtle areas of the code, like good design, best practices, good taste, dry, etc. We often need to prompt it to refactor things as the quick solution it decided to do is not in our best interest for the long run. It often ends in deep investigations about things which are trivially obvious. It is overfitted to use unix tools in their pure form as it fail to remember (even with prompting) that it should run `pnpm test:unit` instead `npx jest` - it gets it wrong every time.

But when it works - it is wonderful.

I think we are at the point where we are close to self-improving software and I don't mean this lightly.

It turns out the unix philosophy runs deep. We are right now working on ways to give our agents more shells and we are frankly a few iterations there. I am not sure what to expect after this but I think whatever it is, it will be interesting to see.

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#355

Post by ivanech »

multisport wrote: post #320

What bothers me about posts like this is: mid-level engineers are not tasked with atomic, greenfield projects. If all an engineer did all day was build apps from scratch, with no expectation that others may come along and extend, build on top of, or depend on, then sure, Opus 4.5 could replace them. The hard thing about engineering is not "building a thing that works", its building it the right way, in an easily unde…

I find Opus 4.5 very, very strong at matching the prevailing conventions/idioms/abstractions in a large, established codebase. But I guess I'm quite sensitive to this kind of thing so I explicitly ask Opus 4.5 to read adjacent code which is perhaps why it does it so well. All it takes is a sentence or two, though.

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#356

Post by lizardking »

vercaemert wrote: post #106
enum wrote: post #103

Earlier quoted context omitted.

I teach at a university, and spend plenty of time programming for research and for fun. Like many others, I spent some time on the holidays trying to push the current generation of Cursor, Claude Code, and Codex as far as I could. (They're all very good.) I had an idea for something that I wanted, and in five scattered hours, I got it good enough to use. I'm thinking about it in a few different ways: 1. I estimate I…

How do you compare Claude Code to Cursor? I'm a Cursor user quietly watching the CC parade with curiosity. Personally, I haven't been able to give up the IDE experience.

When I'm using Claude Code, I usually have a text editor open as well. The CC plugin works well enough to achieve most of what Cursor was doing for me in showing real-time diffs, but in my experience, the output is better and faster. YMMV

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#357

Post by everfrustrated »

ern wrote: post #306
spaceman_2020 wrote: post #54

Earlier quoted context omitted.

I really think a lof of people tried AI coding earlier, got frustrated at the errors and gave up. That's where the rejection of all these doomer predictions comes from. And I get it. Coding with Claude Code really was prompting something, getting errors, and asking it to fix it. Which was still useful but I could see why a skilled coder adding a feature to a complex codebase would just give up Opus 4.5 really is at a…

I have been out of the loop for a couple of months (vacation). I tried Claude Opus 4.5 at the end of November 2025 with the corporate Github Copilot subscription in Agent mode and it was awful: basically ignoring code and hallucinating. My team is using it with Claude Code and say it works brilliantly, so I'll be giving it another go. How much of the value comes from Opus 4.5, how much comes from Claude Code, and how…

As someone coming from GitHub copilot in vscode and recently trying Claude Code plugin for vscode I don't get the fuss about Claude.

Copilot has by far the best and most intuitive agent UI. Just make sure you're in agent mode and choose Sonnet or Opus models.

I've just cancelled my Claude sub and gone back and will upgrade to the GH Pro+ to get more sonnet/opus.

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#358

Post by cma »

mcv wrote: post #316
HawtAds wrote: post #249

Earlier quoted context omitted.

Copilot and many coding agents truncates the context window and uses dynamic summarization to keep costs low for them. That's how they are able to provide flat fee plans. You can see some of the context limits here: https://models.dev/ If you want the full capability, use the API and use something like opencode. You will find that a single PR can easily rack up 3 digits of consumption costs.

Maybe not, then. I'm afraid I have no idea what those numbers mean, but it looks like Gemini and ChatGPT 4 can handle a much larger context than Opus, and Opus 4.5 is cheaper than older versions. Is that correct? Because I could be misinterpreting that table.

You need to find where context breaks down, Claude was better at it even when Gemini had 5X more on paper, but both have improved with last releases.

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#359

Post by sksishbs »

fenwick67 wrote: post #336
multisport wrote: post #320

What bothers me about posts like this is: mid-level engineers are not tasked with atomic, greenfield projects. If all an engineer did all day was build apps from scratch, with no expectation that others may come along and extend, build on top of, or depend on, then sure, Opus 4.5 could replace them. The hard thing about engineering is not "building a thing that works", its building it the right way, in an easily unde…

Another thing that gets me with projects like this, there are already many examples of image converters, minesweeper clones etc that you can just fork on GitHub, the value of the LLM here is largely just stripping the copyright off

It’s kind of funny - there’s another thread up where a dev claimed a 20-50x speed up. To their credit they posted videos and links to the repo of their work.

And when you check the work, a large portion of it was hand rolling an ORM (via an LLM). Relatively solved problem that an LLM would excel at, but also not meaningfully moving the needle when you could use an existing library. And likely just creating more debt down the road.

Re: Opus 4.5 is not the normal AI agent experience that I have had thus far

#360

Post by [deleted] »

mcv wrote: post #133

Opus 4.5 ate through my Copilot quota last month, and it's already halfway through it for this month. I've used it a lot, for really complex code. And my conclusion is: it's still not as smart as a good human programmer. It frequently got stuck, went down wrong paths, ignored what I told it to do to do something wrong, or even repeat a previous mistake I had to correct. Yet in other ways, it's unbelievably good. I ca…

[deleted]
Post reply on HN