Cognitive Debt: When Velocity Exceeds Comprehension • Hacker News Board

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#51

Post by kibwen » Sat, Feb 28, 2026, 5:01 PM UTC

samrus wrote: post #33

Great article. I agree with the argument. But to offer a counter argument, would the same thing not have happened with the rise of high level languages? The machine code was abstracted away from engineers and they lost understanding of it, only knowing what the high level code is supposed to do. But that turned out fine. Would llms abstracting the code away so engineers only understand the functionality (specs, tests…

> would the same thing not have happened with the rise of high level languages?

Any argument that attempts to frame LLMs as analogous to compilers is too flawed to bother pursuing. It's not that compilers are deterministic (an LLM can also be deterministic if you have control over the seed), it's that the compiler as a translator from a high level language to machine code is a deductive logical process, whereas an LLM is inherently inductive rather than deductive. That's not to say that LLMs can't be useful as a way of generating high level code that is then fed into a compiler (an inductive process as a pipeline into a deductive process), but these are fundamentally different sorts of things, in the same way that math is fundamentally different from music (despite the fact that you can apply math to music in plenty of ways).

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#52

Post by Vexs » Sat, Feb 28, 2026, 5:05 PM UTC

softwaredoug wrote: post #25

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

If I’m learning for the first time, I think it matters to hand code something. The struggle internalizes critical thinking. How else am I supposed to have “taste”? :) I don’t know if this becomes prod code, but I often feel the need to create like a Jupyter notebook to create a solution step by step to ensure I understand. Of course I don’t need to understand most silly things in my codebase. But some things I need t…

Almost anything I write in Python I start in jupyter just so I can roll it around and see how it feels- which determines how I build it out and to some degree, how easy it is to fix issues later on.

With llm-first coding, this experience is lost

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#53

Post by Vexs » Sat, Feb 28, 2026, 5:07 PM UTC

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

I don't remember exactly what I wrote and how the logic works, but I generally remember the broad flow of how things tie together, which makes it easier to drop in on some aspect and understand where it is code-wise.

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#54

Post by seba_dos1 » Sat, Feb 28, 2026, 5:08 PM UTC

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

I juggle between various codebases regularly, some written by me and some not, often come back to things after not even months but years, and in my experience there's very little difference in coming back to a codebase after 6 months or after a week.

The hard part is to gain familiarity with the project's coding style and high level structure (the "intuition" of where to expect what you're looking for) and this is something that comes back to you with relative ease if you had already put that effort in the past - like a song you used to have memorized in the past, but couldn't recall it now after all these years until you heard the first verse somewhere. And of course, memorizing songs you wrote yourself is much easier, it just kinda happens on its own.

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#55

Post by TallGuyShort » Sat, Feb 28, 2026, 5:08 PM UTC

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

This is also an area where AI can help. Don't just tell it to write your code. Before you get going, have it give you an architectural overview of certain parts you're rusty on, have it summarize changes that have happened since you were familiar, have it look at the bigger picture of what you're about to do and have it critique your design. If you're going to have it help you write code, don't have it ONLY help you write code. Have it help you with all the cognitive load.

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#56

Post by copperx » Sat, Feb 28, 2026, 5:09 PM UTC

senko wrote: post #35

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

I recently did some work on a codebase I last touched 4 years ago. I didn't remember every line but I still had a very good grasp of how and why it's put together. (edit: and no, I don't have some extra good memory)

Lucky you. I always go "huh, so I wrote this?". And this was in the pre-AI era.

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#57

Post by SpicyLemonZest » Sat, Feb 28, 2026, 5:10 PM UTC

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

I’m very confused by this statement. I routinely answer questions about why we wrote the code we wrote 6 months ago and expect other people to do the same. In my mind that skill is one of the key differences between good and bad developers. Is it really so rare?

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#58

Post by techxploitation » Sat, Feb 28, 2026, 5:13 PM UTC

Forgive me if I'm stating the obvious, but, it is completely plausible and possible to run a separate review of what ai just created, explaining what decisions where made and why, how they affect the existing system and going forward. This review can have a critique section over core failure modes that you have found in ai, or discrepancies unique to your setup. It can even be further condensed from verbose 2 page document into the core relevant explanation, for future references. - I think sometimes SWE's have an ego about needing to understand it entirely self-sufficiently, and so hold back on just asking relentless questions, like a child. 'But why?' 'but why?' 'but why?' until it is revealed, is a valid method in today's environment.

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#59

Post by maqp » Sat, Feb 28, 2026, 5:14 PM UTC

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

A lot of bug fixing relies on some mental model about the code. It manifests as rapid "Oh 100% I know what's causing" -heureka moments. With generated code, that part's gone for good. The "black box written by a black box" is spot on on, you're completely dependent on any LLM to maintain the codebase. Right now it's not a vendor lock thing but I worry it's going to be a monopoly thing. There's going to be 2-3 big companies at most, and with the bubble eventually bursting and investor money dying, running agents might get a lot more expensive. Who's going to propose the rewrite of thousands of LLM-generated features especially after the art of programming dies along with current seniors who burn out or retire.

Re: Cognitive Debt: When Velocity Exceeds Comprehension

#60

Post by SoftTalker » Sat, Feb 28, 2026, 5:14 PM UTC

senko wrote: post #35

pajtai wrote: post #9

The whole premise of the post, that coders remember what and why they wrote things from 6 months ago, is flawed. We've always had the problem that understanding while writing code is easier than understanding code you've written. This is why, in the pre-AI era, Joel Spolsky wrote: "It's harder to read code than to write it."

I recently did some work on a codebase I last touched 4 years ago. I didn't remember every line but I still had a very good grasp of how and why it's put together. (edit: and no, I don't have some extra good memory)

I find this to be the case if it was something I was deeply involved with.

Other times, I can make a small change to something that doesn't require much time, and once it's tested and committed, I quickly lose any memory of even having done it.