There's no reason for software to be slow anymore

Jach 256 points 186 comments August 22, 2026
danluu.com · View on Hacker News

Discussion Highlights (20 comments)

ungreased0675

But software seems to be getting slower and less user friendly by the hour.

tobinfekkes

Wow, my browser's Reader Mode saved my bacon on this one. Otherwise, I would have left immediately. I'm all for speedy, simple, plaintext websites, but it is a negligible amount of work in 2026 to throw some barebones CSS in and make it approachable.

measurablefunc

There is no reason for it to be non-extensible either and depending on the use cases people might want to trade speed/optimization for more runtime customizations which will inherently be slower than pre-baked SIMD regex and whatnot.

thomasjudge

who is Jamie Brandon

bell-cot

The vast majority of users - weighting by the profits they generate for software companies - obviously don't care about "slow". And Munger's Law never cares if you hate its consequences.

killbot5000

As long as there’s a trade off between experimentation and performance, software will always be slightly too slow.

raincole

100% sure software in the coming years will just feel slower and slower.

supriyo-biswas

Well, at least with the RAM crunch that the AI boom has caused, I hope there will be some sort of pressure to write efficient software, otherwise device manufacturers are quite fucked.

newsomix9xl

One article said secure software was here because of AI, this one says it can now be performant. Yet when I ask for code it writes, by default, both slow and insecure code that mostly works. Kinda. As I try to get AI to rewrite it into more secure, less bloated and optimized code is when it starts to randomly crash. Then I read articles about how AI is "moving too fast" and cry.

nemothekid

This makes sense for a verifiable task like a regex engine - but those are clearly defined and I doubt an LLM will have a meaningful speed increase over current human regex engines. Anything else kind of just feels like "make GTA 6, make no mistakes". The ability for you to write fast and correct software is really going to depend on well you can specify your problem, and having the ability to specify correct programs in such detail an LLM can reasonably performance tune it is a big enough reason for me to believe there will still be slow software

gravypod

I recently built a piece of code which downloads a bulk set of data, indexes it for search, and then serves a pretty web UI on top of this with the help of some AIs. Normally I would have reached for sstables, sqlite, etc. This time, because the lookup patterns actually would not have been too efficient on sstables and SQLite would have been overkill, I had an agent take the data structures, pack the text effectively, and build a prefix tree for fast auto completion from the search bar. It was great. I could have done this all before but I wouldn't have. I would have felt sqlite was fast enough. The resulting web server is significantly faster feeling (because the optimized lookup speeds) than an sqlite implementation would feel like. I think engineers building very complex systems now have a lot of performance knobs to twiddle that would have just been too costly for human effort. Since we constrain the responsibilities of the agent slop is less of a problem. We relegate it to defined tasks with clear API boundaries and test harnesses.

panny

>LLMs are causing slow, bloated, code are going to eat crow once they re-write everything in super-optimized assembly LLMs have caused such an increase in ram prices that pine64 is no longer making linux machines. When you can't afford RAM, as a direct result of LLMs, it's going to make your assembly app slower too. Sorry, this is the future you chose.

jeffbee

Eh, not sure. Very few humans do software optimization productively, so I'm not optimistic about machines built by humans, either. Every encounter I've had with agentic optimization involved trying to apply a bunch of myths to an existing code base, in a way that seemed cool (unrolling loops, eliminating apparent branches, SIMD) but which was all pointless because the only credible optimizations were going to come from doing fewer loads and taking up fewer itlb slots and stuff like that.

mtgh2s

we should just have the LLM rewrite everything in Rust :D problem solved

Lerc

Giving an LLM a program that does a well defined thing correctly and asking it to make a faster version and a crapload of tests to show that it performs exactly the same task is a great way to burn through a bunch of tokens and getting a faster program in return. I currently have one running working on a multi path problem trying to make an A* heuristic that produces the same or better score for search time, paths crossed, corners taken (plus a few other metrics, like proximity of opposite direction corners of unconnected paths.) I have another where I'm testing how well it can iteratively rewrite the same program without regressions and successively stricter resource conditions. Instead of progressively adding lines of code to make an over engineered behemoth, starting over with the previous version as a template of functionality lets it consider the problem increasingly holistically

4lx87

Jevon's paradox implies we're getting more fast software, and more slow software. Sturgeon’s law implies the ratio will remain the same. 90% of what ships will be slow, buggy, slop. Just as it was before LLMs.

hardaker

What if we need pretty, rounded, softly opaque corners on all our transparent windows hovering above a gently shadowed background?

0xbadcafebee

"There's no reason" being very different than "we can now do the thing easier". There are still tons of reasons for software to be slow, the biggest of which is priorities. If you want your software to be fast, stop writing it in Python and TypeScript and instead write it in Go, Rust, C++ or C. But nobody's going to do that, because humans are emotional creatures who get attached to things (like programming languages). Or if you want your software to be fast, stop spending your time and money (tokens) on features, and start spending it on profiling log replays to find a bottleneck causing a 50ms delay for the 95th percentile. But nobody's going to do that either, because how slow is too slow? Answer: when it's slow enough to scare the shareholders or annoy the developer on their high-powered laptop. If you want faster/more efficient software, force it to run on a 100MHz CPU with 512KB RAM and a 56k modem. You'll definitely prioritize speed then.

jongjong

> performance work that used to require a person or team that had a rare set of skills can be done by anyone who can type a few sentences This idea is the reason why software will keep getting slower and less reliable. Because it's wrong and yet people believe it. Not only do people believe this, even if they didn't, they would still have the problem that most people (including many engineers) are bad at telling who is a good software engineer. So this means that code will get worse and worse; less performant, less reliable, less secure. It will be impossible to fix because nobody would know what the problems are let alone identify who is able to solve those problems. I don't know how bad it has to get before people understand we have to rebuild everything from scratch on much more rigid guardrails. The essence of the problem is that the LLM does exactly what you tell it. In the hands of a skilled engineer who understands the project, this is a superpower. In the hands of a junior, this is dangerous... Because it will do things that are insecure; it doesn't push back on a user request; it just goes ahead and tries to make it work, even if it's a bad idea and the problem is best solved in a different way.

ehnto

One of the biggest causes of slowness is just waiting for web requests. The fact that so much software is either online or built using the same stack even if it isn't, puts all that software in this blocked/waiting state constantly while using it. Anyone not in the US feels this even more since so much online is US hosted, 300ms for every little interaction adds up quick. If your software has the affordance of a waiting dialogue or loading wheel for many of its UI controls, you are building with this default blocked assumption. Even if you are building something web based, ask yourself if that's actually necessary for your software or if you could build it differently to avoid constant UI blocking.

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