Ask HN: Do you have any evidence that agentic coding works? • Hacker News Board

Re: Ask HN: Do you have any evidence that agentic coding works?

#71

Post by edude03 » Tue, Jan 20, 2026, 4:59 PM UTC

sReinwald wrote: post #57

edude03 wrote: post #4

I have the same experience despite using claude every day. As an funny anecdote: Someone I know wrote the code and the unit tests for a new feature with an agent. The code was subtly wrong, fine, it happens, but worse the 30 or so tests they added added 10 minutes to the test run time and they all essentially amounted to `expect(true).to.be(true)` because the LLM had worked around the code not working in the tests

From my experience: TDD helps here - write (or have AI write) tests first, review them as the spec, then let it implement. But when I use Claude code, I also supervise it somewhat closely. I don't let it go wild, and if it starts to make changes to existing tests it better have a damn good reason or it gets the hose again. The failure mode here is letting the AI manage both the implementation and the testing. May as…

> TDD helps here - write (or have AI write) tests first, review them as the spec

I agree, although I think the problem usually comes in writing the spec in the first place. If you can write detailed enough specs the agent will usually give you exactly what you asked for. If you're spec is vague, it's hard to eyeball if the tests or even the implementation of the tests matches what you're looking for.

Re: Ask HN: Do you have any evidence that agentic coding works?

#72

Post by damnitbuilds » Tue, Jan 20, 2026, 5:07 PM UTC

swiftcoder wrote: post #43

spolitry wrote: post #5

Earlier quoted context omitted.

It seems that people feel code review is a cost, but time spent writing code is not a cost because it feels productive.

I don't think that's quite it - review is a recurring cost which you pay on every new PR, whereas writing code is a cost you pay once. If you are continually accumulating technical debt due to an over-enthusiastic junior developer (or agent) churning out a lot of poorly-conceived code, then the recurring costs will sink you in the long run

"review is a recurring cost which you pay on every new PR, whereas writing code is a cost you pay once."

Huh ? Every new PR is new code which is a new cost ?

Re: Ask HN: Do you have any evidence that agentic coding works?

#73

Post by mrdependable » Tue, Jan 20, 2026, 5:44 PM UTC

SatvikBeri wrote: post #52

Sure, here are my own examples: * I came up with a list of 9 performance improvement ideas for an expensive pipeline. Most of these were really boring and tedious to implement (basically a lot of special cases) and I wasn't sure which would work, so I had Claude try them all. It made prototypes that had bad code quality but tested the core ideas. One approach cut the time down by 50%, I rewrote it with better code an…

Why is your babysitting bill so complicated?

Re: Ask HN: Do you have any evidence that agentic coding works?

#74

Post by 7777332215 » Tue, Jan 20, 2026, 6:06 PM UTC

Don't use it myself. But I have a client who uses it. The bugs it creates are pretty funny. Constantly replacing parts of code with broken or completely incorrect things. Making things that previously worked broken. Deleting random things.

Re: Ask HN: Do you have any evidence that agentic coding works?

#75

Post by antonvs » Tue, Jan 20, 2026, 6:12 PM UTC

znsksjjs wrote: post #61

antonvs wrote: post #27

Earlier quoted context omitted.

> Anyone who claims AI is great is not building a large or complex enough app That might be true for agentic coding (caveat below), but AI in the hands of expert users can be very useful - "great" - in building large and complex apps. It's just that it has to be guided and reviewed by the human expert. As for agentic coding, it may depend on the app. For example, Steve Yegge's "beads" system is over a quarter million…

> For example, Steve Yegge's "beads" system is over a quarter million lines of allegedly vibe-coded Go code. But developing a CLI like that may be a sweet spot Is that really a success? I was just reading an article talking about how sloppy and poorly implemented it is: https://lucumr.pocoo.org/2026/1/18/agent-psychosis/ I guess it depends on what you’re looking to get out of it.

I haven't looked into it deeply, but I've seen people claiming to find it useful, which is one metric of success.

Agentic vibe coding maximalists essentially claim that code quality doesn't matter if you get the desired functionality out of it. Which is not that different from what a lot of "move fast and break things" startups also claim, about code that's written by humans under time, cost, and demand pressure. [Edit: and I've seen some very "sloppy and poorly implemented" code in those contexts, as well as outside software companies, in companies of all sizes. Not all code is artisanally handcrafted by connoisseurs such as us :]

I'm not planning to explore the bleeding edge of this at the moment, but I don't think it can be discounted entirely, and of course it's constantly improving.

Re: Ask HN: Do you have any evidence that agentic coding works?

#76

Post by SatvikBeri » Tue, Jan 20, 2026, 6:14 PM UTC

mrdependable wrote: post #73

SatvikBeri wrote: post #52

Sure, here are my own examples: * I came up with a list of 9 performance improvement ideas for an expensive pipeline. Most of these were really boring and tedious to implement (basically a lot of special cases) and I wasn't sure which would work, so I had Claude try them all. It made prototypes that had bad code quality but tested the core ideas. One approach cut the time down by 50%, I rewrote it with better code an…

Why is your babysitting bill so complicated?

There are several different types of work they can do, each one of which has a different hourly rate. The time of day affects the rate as well, and so can things like overtime.

It's definitely a bit of an unusual situation. It's not extremely complicated, but it was enough to be annoying.

Re: Ask HN: Do you have any evidence that agentic coding works?

#77

Post by crq-yml » Tue, Jan 20, 2026, 6:33 PM UTC

sirwhinesalot wrote: post #9

The only approach I've tried that seems to work reasonably well, and consistently, was the following: Make a commit. Give Claude a task that's not particularly open ended, the closer to pure "monkey work" boilerplate nonsense the task is, the better (which is also the sort of code I don't want do deal with myself). Preferably it should be something that only touches a file or two in the codebase unless it is a trivia…

TBH I think the greatest benefit is on the documentation/analysis side. The "write the code" part is fine when it sits in the envelope of things that are 100% conventional boilerplate. Like, as a frontend to ffmpeg you can get a ton of value out of LLMs. As soon as things go open-ended and design-centric, brace yourself.

I get the sense that the application of armies of agents is actually a scaled-up Lisp curse - Gas Town's entire premise is coding wizardry, the emphasis on abstract goals and values, complete with cute, impenetrable naming schemes. There's some corollary with "programs are for humans to read and computers to incidentally execute" here. Ultimately the program has to be a person addressing another person, or nature, and as such it has to evolve within the whole.

Re: Ask HN: Do you have any evidence that agentic coding works?

#78

Post by swiftcoder » Tue, Jan 20, 2026, 6:38 PM UTC

damnitbuilds wrote: post #72

swiftcoder wrote: post #43

Earlier quoted context omitted.

I don't think that's quite it - review is a recurring cost which you pay on every new PR, whereas writing code is a cost you pay once. If you are continually accumulating technical debt due to an over-enthusiastic junior developer (or agent) churning out a lot of poorly-conceived code, then the recurring costs will sink you in the long run

"review is a recurring cost which you pay on every new PR, whereas writing code is a cost you pay once." Huh ? Every new PR is new code which is a new cost ?

> Every new PR is new code which is a new cost ?

Every new PR interacts with existing code, and the complexity of those interactions increases steadily over time

Re: Ask HN: Do you have any evidence that agentic coding works?

#79

Post by proc0 » Tue, Jan 20, 2026, 7:41 PM UTC

linsomniac wrote: post #14

proc0 wrote: post #3

My experience is the same. In short, agents cannot plan ahead, or plan at a high level. This means they have a blindspot for design. Since they cannot design properly, it limits the kind of projects that are viable to smaller scopes (not sure exactly how small but in my experience, extremely small and simple). Anything that exceeds this abstract threshold has a good chance of being a net negative, with most of the co…

>Anyone who claims AI is great is not building a large or complex enough app I can't speak for everyone, but lots of us fully understand that the AI tooling has limitations and realize there's a LOT of work that can be done within those limitations. Also, those limitations are expanding, so it's good to experiment to find out where they are. Conversely, it seems like a lot of people are saying that AI is worthless be…

Right, it has a lot of uses. As a tool it has been transformative on many levels. The question is whether it can actually multiply productivity across the board for any domain and at production level quality. I think that's what people are betting on, and it's not clear to me yet that it can. So far that level looks more like a tradeoff. You can spend time orchestrating agents, gaining some speedup at the cost of quality, or you can use it more like a tool and write things "manually" which is a lot higher quality.

Re: Ask HN: Do you have any evidence that agentic coding works?

#80

Post by proc0 » Tue, Jan 20, 2026, 7:47 PM UTC

antonvs wrote: post #27

proc0 wrote: post #3

My experience is the same. In short, agents cannot plan ahead, or plan at a high level. This means they have a blindspot for design. Since they cannot design properly, it limits the kind of projects that are viable to smaller scopes (not sure exactly how small but in my experience, extremely small and simple). Anything that exceeds this abstract threshold has a good chance of being a net negative, with most of the co…

> Anyone who claims AI is great is not building a large or complex enough app That might be true for agentic coding (caveat below), but AI in the hands of expert users can be very useful - "great" - in building large and complex apps. It's just that it has to be guided and reviewed by the human expert. As for agentic coding, it may depend on the app. For example, Steve Yegge's "beads" system is over a quarter million…

Anything above a simple app and it becomes a tradeoff that needs to be carefully tuned so that you get the most out of it and it doesn't end up being a waste of time. For many use cases and domain combinations this is a net positive, but it's not yet consistent across everything.

From my experience it's better at some domains than others, and also better at certain kinds of app types. It's not nearly as universal as it's being made out to be.