Write code like a human will maintain it
227 points - today at 1:33 PM
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Mine starts with “Enter plan mode. Examine the differences on this branch vs. main. Consider: ...” and proceeds to a bullet list of things.
Any time I notice something in code review and have to get the agent to fix it.. I throw it on the list!
My list is like 200 items now. Know what? Agents don’t care that they just got a wall of generic feedback, they happily look into all the bullet points.
I added “ensure the new things aren’t duplicating code that already exists elsewhere” and it gave me such a surprise - it really truly started planning cleanups!
We are just scratching the surface. We have to give tools to our tools so they can use them to be better tools for us.
To be honest I'm not sure how true this is. I think it's more that there does seem to be quite a baked-in bias to repeat basic structures and not reuse (much less come up with) abstractions. So where that is the existing pattern it looks like it's keeping with that, when in reality it would often do that either way.
There have been many cases where I've started a piece of work by laying down very rigid abstractions and a few examples of using them, and I explicitly prompt to not only exclusively use the specific abstraction API but also copy the way I've used it. And the (frontier) LLM does neither, it just steams ahead re-implementing things from scratch from bottom up basic structures, partially and often totally ignoring the abstractions.
I don't know exactly why this should be the case but my naive suspicion is that there's just an awful lot of this type of stuff in the masses of training code and the weights just somehow 'know better' how to get results this way, rather than using your more novel abstractions/patterns.
To me building on multiple scalable systems this has been the most dangerous part of LLMs. On a good codebase it will work good, but it will maek it worse, so you keep using it, till it doesnt work and then you have to pay the bill and fix for what you didn’t build before.
If you put an agent on a fresh codebase 2 things are often given:
-> You have a mental model of the code -> The code is somewhet concise
After multiple iterations both is lost and LLM performance degrades. To solve this you can regular refactor, but it’s not a nice experienc. So my best solution is:
I use LLMs for exploration and for review, but I write the code myself. I find it hard to believe why so many engineers try to avoid it. It’s not consuming much of my time. And it’s actually the most enjoyable part.
Sometimes I race AI i give it a prompt /bug to fix and at the sametime im greping/symboling through the codebase and tryto fix it myself. AI isn’t always faster.
"Add comments to your code under the assumption that the next person to maintain it is a homicidal maniac who knows where you live"
1. Created a "coding" skill with every practice I posted on my blog website, as well as a bunch I had in the queue to blog about but never got a chance, summarized into "do this" kind of language. This is more or less good for any PL, but a bit Ruby-slanted.
2. Created a "rails" skill because that's my framework, where similarly I explained my approach to architecting Rails apps.
3. Created a "writing" skill where I literally fed it my entire blog, and tried to get it to write more like me (mixed success, weaker models did better for some reason, but I haven't tried the GPT-5.6 series yet).
4. Next, I really wanted it to format code exactly like I would, even things like "let's make this `if` into a ternary, let's split these assignment groups with a line break, let's vertically align here, but not there", but with GPT-5.5 (my primary driver up until yesterday) there's almost no way to make a skill of reasonable size that will be consistently applied. So instead I instructed the agent to write me a Rubocop cop for every single situation I ever encounter where I would've formatted code slightly differently. This was quite powerful, because I usually thought of linters as enforcers of objective consistency decisions in the codebase, but this was me going full format nazi on the agent. And the nice part is that these cops can contain some non-autocorrectable feedback, which AI will follow.
5. I'm working on a review loop where the most easily missed parts above get double checked. This is the first thing I'm doing with pi subagents. (I feel like I'm getting better results if I don't use subagents for code exploration, other tool calls). The idea here is that I want reviews to be in the implementation loop. I always read/review code in the end, but so want it to have gone through the review loop before it gets to me. Since implementation is already context-heavy, I want to be able to orchestrate this loop without adding to the implementation context.
6. I'm also adjusting all of the above for GPT-5.6, because it requires less guidance, so I'm carefully trimming the verbiage to save tokens.
So far the results have been surprisingly good. I want to experiment with GLM-5.2 running under these constraints.
One invariant in all of this: I read the code. My end product is not working software, it's good code (which also incidentally produces working software).
There's a huge cost to Clean-Code-style DRY'ing of your codebase which is that you wind up creating all kinds of little functions that all add cognitive overhead to reading your codebase, and that premature DRY'ing can lead to picking the wrong abstractions.
If you can tolerate a bunch of copypasta, you can sit back after you've written 5,000 or 10,000 lines of code and can look at the actual result, instead of speculating, and make better-informed decisions about how to clean the codebase up. If you're making those decisions the first time you copy a bit of code around, you can wind up making a worse mess, since you often don't know where you're going.
Maybe someone has the perfect claude.md that solves this problem but I have not seen it.
disagree, then you end up with something this this
function checkAll(target, conditions) { return Object.entries(conditions).every(([path, expected]) => { const value = path.split('.').reduce((o, k) => o?.[k], target); return typeof expected === 'function' ? expected(value, target) : value === expected; }); }
and const ok = checkAll({ user, account }, { 'user.isActive': true, 'user.isSuspended': false, 'account.status': 'open', 'user': u => u.hasPermission('read'), // predicate for the trickier bit });
how is that better?
Where it really, really struggles for me is in existing complex infra codebases.
* define the software layers, their function, and the max depth allowed
* establish a corp code formatter for each language, along with a process to PR it
* establish a business vocabulary and what the terms mean
* establish a data dictionary, make it part of the database schema/table/col comments
Are far more successful with LLMs. You _should_ have been doing this years ago, but with LLMs its a super power.
(Because it's true.)
I started using AI with the best intentions. Checking everything before committing. Improving output by hand if it didn't quite follow the existing code style guidelines or variables were not named as well as they should be. Or if it did something sloppy or hacky.
Now, AI GOES BURRRRRRRRRRRR! If the tests pass it's good to ship. AI can deal with the problems it may create. No problems so far.
Taken from: https://github.com/zakirullin/cognitive-load/blob/main/READM...
At a minimum, there should be precommit checks and CI workflows that cause PRs to fail if the documentation is not up-to-date and synced with the other docs.
Then regular codebase analysis for improvement. This is where you find the bug sources, make new modules for consolidation, and get those +5000/-4000 PRs that people stuck in the world of manual code review hate.
Easier said than done to be honest, especially if there are many people (and their agents) pushing code. It’s hard to keep up these days.
Getting away from stuff like this is exactly why I want to use AI. When I say "implement this for idle but active users," I _want_it to define isUserActiveIdle() and stuff these 4 conditionals in it. Having to check the generated code for stuff like this undoes, like .... all the benefit of using AI.
AI makes all these little decisions for us. I can about some of these decisions. I just want to notice when it's doing this without having to make my eyes bleed reading 10k lines of generated code a day.
You'd be surprised how readable this makes the code when XXX is about the size of your vertical screen and Y is relatively small.
code review has always been a liability fig leaf. it is much harder to understand a system from reading the code than writing the code. if AI can write code 100X faster than humans it is simply impossible for humans to do real code review. effectively it is just pretending to do code review, and then running unaudited code without the proper systemic security guardrails in place.
One pattern I've really been enjoying lately has to do with a language called haxe. It's designed to be compiled into other languages (java, python, others). There's this extension called reflaxe which lets you make mini compilers for compiling haxe into pretty much anything.
So if I have anything with duplicate structure... like maybe I want the CLI subcommands to resemble the http API.
$ foo bar --baz 6 # produces similar output as HTTP GET /foo/bar?baz=6
...and `docs/generated/foo.md#bar` should have documents both the CLI and the http usage. Then I have the LLM maintain a haxe source of truth and then have it compile that source of truth to the other stuff.Previously I was using OpenAPI spec's and generators for this, but they wound up feeling like a black box that I ended up debugging all the time. The reflaxe setup is much more generic. So you end up with this mountain of generated code, but unlike LLM-generated code it's obviously generated (in .../generated/thingy.py or whatever) and a comment at the top of the file says where to look to learn how it's generated). I'm generating docs this way, accessor functions for database tables and SQL for making those tables, matching clients and servers in different languages... it replaces a lot of purpose built tools with just one, and LLMs are pretty good at it.
So even though the repo is large, the parts of it that are authoritative remain small. I find LLM's manage this boundary much better because it's so crisp an in their face. But they have to be told to do this, otherwise they'll just create context-size problems that they'll later struggle with.
Of course you could do this with yaml files or some such, but unlike yaml, haxe has a type system, you can write tests in it, so the agent can notice fundamental flaws before the generation happens... with yaml those flaws would be propagated into the generated code before they'd get noticed.
Otherwise what I have found is that the LLM will add a new if statement which will handle the newly discovered issue and you start stacking them ifs. As the article mentions LLM's unlike humans aren't lazy, they will copy, paste add patches for every issue, why bother think and understand root cause :d.
So as part of our review we have a rule against that as well.
Of course, this doesn't solve the overall issue that agents don't write code like you and still requires a lot of human attention in planning and code review out to clean up leftover issues, and e.g. challenge bad assumptions about architecture and real-world context. A human is still very much needed to cull the slop (or, more gratuitously: align the agent). But IME it does help avoid a lot of pitfalls and makes the code high quality a lot more quickly.
Funny enough, discussed this yesterday
Stop Optimizing Code for Humans https://youtube.com/live/eLn4-XA-KdQ?feature=share
For personal projects, I can trust that I myself will be maintaining things so I still write things like it matters, but I do not extend the trust to others.
You can have all the prompts you want on top of this, but if you don't have this automated stuff running behind the scenes, you aren't serious about these issues.
Looking through some of these comments here, I see lots of people rewriting concrete rules in markdown willing to spend tokens on the hope AI won't miss it where an actual program won't.
— John F. Woods (1991)
bottom up AI use seems a godsend compared to the corporate AI rat race.
i setup some slop reporting systems and ensured my boss knows theyre great starting points but serious use requires real time investment.
I’m pretty sure many people who use AI to write emails or blog posts add "make it sound like a human wrote it" to their prompts. We all know what the result usually looks like.
If AI is writing my code, I'd rather have it focus purely on correctness and efficiency than on making the code easy to read.
heck! I might even ask it to imitate Arthur Whitney’s style.
/s