2x, not 10x: coding with LLMs in 2026
obryant.dev93 points by tnisonoff 5 days ago
93 points by tnisonoff 5 days ago
While I agree with the premise, I think this angle only applies on work one was going to do no matter what. The real power of these tools is that there are so many ideas people would like to try, but never have the time or motivation to pursue.
So the comparison is not only "built with and without LLM" but "would you even build this if you didn't have the LLM?". The gap in productivity in this case is much more wide.
I think this isn’t always a net positive either though. I’ve seen some devs waste a lot of time using AI to build something that was a bad idea to begin with.
Without AI they might have first spent more time validating the idea was worth it.
Agree so much. So many small bugs, nits, tweaks I just send off to an LLM agent to figure it out.
The way I see it you should calibrate the way you work with LLMs based on how confident you are on that specific area, and if it's your responsibility to own/understand it. Here's how it feels for me:
* Learning stage: 0.5x - 1x. I change my system prompt to teacher mode, taking the productivity hit for actually learning the system/tool pays off dividends later. I change my system prompt to "teacher mode" and slowly loosen it as I get more confident.
* Working-knowledge: 2x - 3x. Once I am ramped up enough I feel like I can get a decent productivity boost. Most of the time is spent at the planning stage. This is my mode for areas I don't really own or care about, just need to get work done.
* Mastered: 10x+ I have been doing web front end for 12+ years, I can quickly review plan/implementations and for my initial prompt I already know most of what I want built.
1x == my speed before AI
> * Mastered: 10x+
This really needs to be calibrated to the type of work and complexity.
I can actually believe that LLMs would speed up basic web dev work in small, simple codebases 10X for simple requests.
These conversations usually turn into people talking past each other because they’re working on different things. For other less routine and more complex work, expecting a 10X productivity boost is not realistic at all. It doesn’t matter how good you get at writing prompts and reviewing plans. LLMs just don’t solve everything for you in a good way. Some times the true nature of the problem is revealed while implementing it and by deferring everything to an LLM you spend days throwing tokens at the wrong thing. There is a lot of work where the LLM speed up comes from helping you quickly search docs and codebases and double check your code, but handing the entire thing off to an LLM isn’t reasonable. These tasks aren’t going to reach this mythical 10X productivity boost that is genuinely achievable for much simpler work.
Some domains don't have the established regularity of architecture that it takes to achieve 10X efficiency. Two I can think of off the top of my head are embedded systems, with a variety of sensors, outputs, processing power, and memory, and novel protocols like ATProto, for which training data is thin on the ground.
Hey, could you share the prompt you're using for "teacher mode"?
Someone posted their AGENTS.md some time ago, that is used in practice to teach their students[1]. That might be useful to you in this context as well.
I'm not sure about the x, but the first thing that arises from that is, I feel like in my case it's way higher than 2.
The 2nd thing is, how do I measure that.
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In my case, the details of my work (Kinda DevOps, kinda Senior Dev) makes it that having an LLM to do the heavy lifting allows me to do things not only faster, but better, and across domains I do not hold expertise on.
An example of the effect of LLMs in my daily work is that I'm in the middle of a PHP upgrade for a rather large legacy application, and the "heavy lifting" is really out of the scale, letting me concentrate on what really matters, while at the same time if I do keep "the harness" tight I'm certain the results are the correct ones. Also correcting course is just as cheap.
Not having to worry on the tooling on exchange has the incredible desirable result of my velocity being incomparable to what it was before.
Then we have the side effect of how easy to do transfer knowledge: Rather than telling the QA guy how to do the work specific for this task, I defined a set of files (.md documents, skills, an off-the-shelf customised MCP server) that assist QA into doing the work in a way that helps me do my job better and faster.
There's also a clear possibility that what I'm doing will expand to the rest of the team I am in, completely altering the way in which we approach development.
If we take 'x' as 'mileage', yours might vary. Mine has, and I'm baffled at the positive net results I AM getting.
Also, this what I do (coding?) is extremely fun again.
Being able to work close to the speed of thought is the best high.
> allows me to do things not only faster, but better, and across domains I do not hold expertise on.
How would you know it's better when you have no expertise?
This reminds me of themes I recently saw in [Harness Engineering is not Enough: Why Software Factories Fail](https://www.youtube.com/watch?v=Ib5GBkD555M) (Warning: the last 3 slides seem like an advertisement). One thing I liked is how Dex has a little graphic he glossed over showing software development is
- 25% planning & aligning with other teams
- 25% coding
- 25% testing/verifying
- 25% code review/rework
One argument was that agentic coding speeds up that coding part a bunch. So maybe there's 2x speedup in coding. But that's only a small speedup in the totality of everything software engineers do.
AI is great because my job is a lot easier, but it produces some extremely crappy code that would've NEVER passed a code review 1 year ago.
You could argue that it speeds up development by 5X or more, but then it slows down testing/verifying, code review, and in many cases it makes it impossible to review/rework by hand.
I just do what I'm told at work but even though I'm sure I'm in the minority I'm extremely skeptical that LLMs can produce any good-quality code.
Looks to me like we've just lowered the bar--by a lot--and stopped looking at the code that goes out. Every time I look into how Claude implemented something it's completely insane, with no way to refactor it or maintain it in the future.
> So maybe there's 2x speedup in coding. But that's only a small speedup in the totality of everything software engineers do.
Amdahl's Law should be familiar to anyone with a 4y computer science/engineering degree. Why aren't they applying it to their own throughput?
Well, there’s probably several reasons:
1) because they’re not doing those others spheres of work
2) because they don’t think about the work
nor how tired they are afterwards
3) they’re proselytizing AI work as the future and
that conflicts with that vision
4) the other shoe hasn’t dropped
5) they really don’t see it
6) some people genuinely hate programming and this
helps them skip that.
The other hard to measure part is that I see/hear a lot of LLM usage going towards dev work that was never prioritized before.
Suddenly devs who were cranking out features with no interest in infrastructure are attacking giant refactors to make the code more understandable to the LLM.
Other devs are using LLMs to build themselves quality of life SDLC tools completely separate from the core code base.
Plenty of other examples of this.
The quality of my bash scripts is 100x what they used to be. Proper help messages, flag parsing, functions, internal variables, using sed all the time (I could never wrap my head around that).
Of course, the main issue is that they’re completely undebbugable now. My bash scripts used to be a sequential list of commands, now they’re 500 lines of variable laden functions.
Is my life any better? Dunno. But it’s satisfying (until there’s a bug)
> the main issue is that they’re completely undebbugable now
Well, that means the quality actually dropped then :). Looking impressive isn't equal to quality, understandability and reliability is
Not necessarily…. As with all engineering choices there are tradeoffs involved. There can be both advantages and disadvantages to using AI to build scripts. And more likely than not you’ll need AI to help debug the scripts when they have issues. Real tradeoffs to consider.
I switched to js for dev related scripting after seeing how much python scripting is used for portable c++ projects like chromium.
A node glob() or a regexp string.replace call is probably easier to read than spaghetti shell.
And your llm might do a much better job of creating clean, readable and testable code.
Just one more data point but this is what I’m seeing too. The extreme ‘ruthless’ prioritization has stopped and devs (who want it) have breathing room to make the enhancements they’ve been wanting all along. Turns out what is good for AI is also good for regular old school SDLC. All you have to do is say it will make AI more effective.
I use CC to do the testing and verifying in multiple deployment environments. It’s faster at things like coming up a plausible test payload or ten, querying a bunch of metrics from datadog, querying and verifying state from a db before and after testing, scanning all the deployed logs for relevant errors. For me that has been more of an uplift than the coding. I still feel like communication it’s worst at. So writing tickets, getting a decision out of a group, documenting only the important things, etc. it’s still not that good at
When I approach a new area or task I first explore it, by hand, and implement, by hand, the task. This way, I get a deeper understanding and it gives me some momentum to llm the rest of the related tasks. Till I loose enough grip to "re-dive in" that area and to again, do stuff my hand. Some tasks, I only do by hand, and some tasks, I only use llm for.
Really depends on the task, my the project and on, and honesty, my instrest and availability at the moment.
I think LLMS have reached to a point where now its just about money. you have to decide whether you really want to spend your tokens to do X or you can just do it yourself and use the tokens for something else.
> Never write READMEs, docstrings, or comments. I will write those myself later. And yes, I really mean this.
The precise and rigorous practice of “engineering” in 2026.
Does the number × depend on how big your thinking is? If you are only 2× then you need to think bigger, aim higher, etc. I think the limit on the 2× is not the ai? Where is the limit now? I think it's unknown.
Definitely feels like a lot more than 2x to me. Any time it feels like the agent is taking a long time I have to look in the mirror and say to myself "What could you have done in 5 minutes?"
I spent 30min with Opus 5 generating some CSS and components for my Phoenix LiveView template project (which I use for starting new projects). Then I spent around 5 hours parsing and cleaning up the output. I could of course not have done that, but since it's my spare time project I can care about the code and quality.
I did get wins for sure (and I did save time), and I'm sure most people wouldn't even spend five minutes cleaning up, but this is definitely one place where people talk about different things regarding whatever x speedup they get.
You still have to know what you’re doing. That came from years of doing it by hand. Where is that necessary experience going to come from for the current and future generations of juniors?
All these hot takes that LLMs are -10x, 100x, 2x are kind of silly. It really depends on:
What you are using it for? What language, what framework, how many LOC, what domain, how much docs can the LLM read, etc etc.
What are you optimizing for? Cost? Human knowing how your code works? Getting something out the door?
How Good You Are at Prompting the LLM for THAT specific set of parameters?
I find AI can save me like 5x time on something, and in other cases it's wasted 5x time. Overtime I'm hopefully learning how to use it better.
I mean the "x amount" is relative to your existing skill level, right?
It's worth asking ourselves "why does the x amount matter?" I get the desire to define KPIs to estimate productivity gains. But this all seems to be—rather rapidly—leading to an increasingly dehumanized reality (both figuratively and literally) so we can...produce more software? I love building software, and I enjoy using LLMs to help me do it, but there's just this weird vibe I can't quite shake about how we're trying to quantify all of this.
0.25x because I scope bigger now and then I may get a few "free" React components but largely doing all that work of putting it together.
Wouldn't trade it though. Feel like I can overall do more with less time and energy.
At the end of the day, AI is making me work more (good thing). If you count that as productivity, then sure.
200x coding with LLM
> As for documentation, I've found this simple instruction to vastly improve LLMs' output:
> Never write READMEs, docstrings, or comments. I will write those myself later. And yes, I really mean this.
This is quite validating as I came to the exact same conclusion myself. We’re required to use an LLM for every task at work that touches code†, and I was really struggling to get Claude to stop with the long waffly comments that reiterate the next few lines of code in 3x as many characters, making contextless references to subtasks in whatever harness du jour we’re using this week.
No amount of examples or explanation of what I wanted would make it stop. And then I realised of course, I’m asking something which has no concept of meaning (or, indeed, anything) to only add meaningful comments. More fool me I guess.
Of course, it’s ultimately pointless given all of my colleagues are regularly opening PRs with more comments than code anyway. 80% of my code review responses these days are just increasingly exasperated “pointless comment, please remove”.
† This is just as infantilising as it sounds, by the way
I have the opposite problem with Code, it barely writes any comments even for fairly complex C++ code blocks (systems programming stuff), have to prompt it to add extra details about why it did something. Request in agents.md doesn't seem to help much.
+10, I can't stand AI-generated comments. Half the time they are paragraph-length translations of every 5 lines of code into English prose, or just regurgitating whatever prompt they were given. When they actually try making high level comments they are worse than useless. It's really hard to put into words exactly why. It's something about how they are very verbose, but at the same time vague and stated in a slightly-off manner. Or they will introduce new terminology not reflected in the code's nomenclature, sometimes terms that are just synonyms for terms that the code already uses. Something about it makes me instantly distrustful of any information the comment may actually convey.
locally correct and globally incoherent is how they seem to me. I, and a number of folks I have talked to, find some of them incomprehensible. Like each sentence makes sense, but the overall thing does not.
It's because they don't really have a mental model. RL with Verifiable Rewards can reward working code, but it can't tell you whether the prose make sense or not. In theory RLHF should be good with this. In practice, it appears to be a measure difficult to quantify and steer. I am not an insider though. So it's just a theory.
I have the same impression. It is an interesting phenomenon. Is it one of the ways we will gradually learn that AI in the form of LLMs is fundamentally lacking?
I use AI all the time, it gives a tremendous boost in speed for many tasks and it is most certainly here to stay, but there is something off about certain things, like code comments. Like a weird person.
I kind of wander if the comments are intentionally bad, providing programmers something to bike shed about. A sneakier approach to the flattery the models used to so use so heavily.
You can create a PostToolUse hook [0] which will automatically chastise Claude to shrink comments to one line. It's not perfect but better than the sea of prose it tends to generate by default. Bonus is that it would apply to your colleagues as well!
[0] https://github.com/chrisvariety/branch-fiction/blob/deb37f2b...
I'm in the same boat. We have very little documentation where I work, and one of my goals was to improve that as I got onboard. We have a newer dev that started ripping +3K, +5K, +10K line PRs against our documentation repository.
I have tried to shut it down, it immediately nullifies the docs and make it genuine slop.
I truly believe that documentation should be human written and human readable. It's all of the stuff that AI does NOT pick up on. Small inconsistencies, only the necessary details. IE: Don't just rewrite the code that we have into readable english (We are software developers after all. We can read code.) - comments / documentation to me has always been the "in between the lines" stuff that can't be put into the code.
> We’re required to use an LLM for every task at work that touches code
Why not just write the code in the prompt so LLM can paste it.
I've found a variant of the Gell-Mann Amnesia effect with regards to LLM coding. They're really magical if you're not familiar with the language, domain, or frameworks you are trying to use. But if you're familiar with those things then you'll often catch them lying to your face and producing a lot of plausible nonsense.
> Never write READMEs, docstrings, or comments.
I found that latest codes don't write comments in code by default. And when they do, they write stupid shit like "This was code that did X, it was now removed".
You have to explcitly prompt them to write comments in code. They are still useful for you, the user. But are arguably useful for the model, too, given how many of them (especially Claude) only reads small chunks of files. So I'd rather have code comments than it reproducing a picture from incomplete data.
A small mention in your user-wide Claude.md (or Agents.md or whatever you use) about the desired types of comments goes a long way. The typical "why, not what", clarifying larger-picture stuff, and everything else you find in every book on code quality
This is a dated take to me. I think the next stage in unlocking productivity is so called "loop engineering"; figuring out how to effectively not read all the code while ensuring quality. To me that means implementing statistical quality control and formal methods.
Before I get there I have to figure out how to reliably audit plan adherence. The problem is that when the specs are in natural language, as they are, you need a fallible LLM to verify it.
I agree that removing human from the loop is the next stage, but we're not there yet beyond small programs.
Agents left alone tend to create so much tech debt, that once the program becomes so messy that they can't fix one bug without creating two new bugs, it's too late to even clean that up.
The program will be super tidy in superficial aspects that linters catch (everything neatly formatted and verbosely commented), and roughly appear to do what it's supposed to do, but everything in between will be "I can't even".
We need something else than formal methods, because the problem is usually in lack of simplicity - you get four versions of the problem solved in four times in four in different ways, each uniquely flawed and just incompatible enough with the others that unifying them is too big and hairy for the agent, and will result in eight different glue adapters written in the process.
This will be a deeply unpopular opinion, but I have an 80k line Go project I've created where I haven't read the source, but would absolutely stake its quality against most hand-written projects of a similar size[0].
Recent LLMs struggle with the author's stated issues only inline: they're entirely capable of going back and evaluating codebases to find architectural issues and LLM slop signatures, especially when you use other models to check one model's output. This wasn't true until Fable-class models, but it's true now.
>As such, I use LLMs mainly to produce a rough draft of the code which I then iterate on heavily, at least until I like the general structure
Tell me you just started with agentic programming without telling me you just started using agentic programming.
Look, don't get me wrong: new folks learning tech should absolutely write articles about it! But their claims might very well change once they learn more .. and I strongly suspect that will be the case here.
Tell me you're bad at software engineering without telling me you're bad at software engineering.
Tell me you're bad at people skills without telling me you're bad at people skills
> As such, I use LLMs mainly to produce a rough draft of the code which I then iterate on heavily, at least until I like the general structure.
Weird… I would have said this was how it was about 2 years ago, but no way in 2026.
... the official return of pair programming! The best part: LLM's save you from having to argue with a human. Added bonus: now you get to master two tools instead of one.
Even this is overstating it IMO.
I already convert from multipliers to percentage of increase, so when someone claims 10x they very likely mean +100% productivity, and here 2x means +20% productivity, which seems about right. Nobody that was normally productive before LLMs has suddenly 10x'ed their output now.
The problem is that 20% productivity when it comes to generating code, really doesn't translate in 20% productivity increase overall, when you take into account the fact that the code quality is worse, the fact that writing code is actually not the majority of your time spent, and that people get burnt out from the usage.
My observation is that AI tools generally make people /less/ productive. They are more productive in that they produce more stuff, but they are less productive in that the stuff they are producing has lower inherent value delivery. The primary place where I see this in software teams as a Product person is in document creation. If you are using an AI tool to produce internal documents, this is likely a net-negative value activity that actually reduces the overall productivity of the team. Why? Because writing is thinking. By handing off document creation to an LLM for a document that's supposed to communicate important details between teams (e.g. technical design docs, requirements docs, strategy docs) you are actually handing off thinking, or rather handing off not-thinking as AI tools cannot "think". The outcome of is poorly "thought out" slop that generates more work for everyone involved to resolve /or/ everyone simply ignores the document and the previous processes stop being useful.
If anything, I'd say AI tools in /most/ enterprises as people are trying to use them now are at least a -30% of productivity. If used correctly for taking a human-written/thought requirements doc, converting it into an interactive prototype that can be critiqued and ultimately included as part of the solution alignment within the requirements doc, and then is handed to an engineering team that is effective at using humans and AI to produce code, then it's probably a benefit. But most businesses lack the internal rigor, quality culture, and data governance to support properly applying AI tools in a high context manner internal to their business.
Have you worked with codebases where people produced slop even before LLMs? In such codebases LLMs are a godsend. They can churn around huge amounts of code and find needles in the haystack.
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Does a 60x speedup count? Are you still copying and pasting from chatgpt, because if so your definitely doing it wrong.
Wait, how about an infinite speedup? A friend of mine couldn't code, and now he can. So he is infinity-x better at coding thanks to LLMS!
Take that, you mere 10x-ers! Your days are toast!
Left behind, as the infinite-x rockstar developer roars off on their motorbike, trailing a plume of dust behind
If 60x was a thing, we would see many fantastic products appearing on the market, every product would have improved or goten major new interesting features. Yet it hasn't really happened.
I believe I have seen 60x improvements on certain classes of bugs. Just not on development as a whole
And I've also seen the other side, where vibe coding on projects that had bad code quality to start with leads to bug riddled messes. Projects with beautiful and elaborate test harnesses, that break seconds after contact with a real human user