Hacker News: menaerus

New comment by menaerus in "We see something that works, and then we understand it"

menaerus — Tue, 12 May 2026 06:21:36 +0000

I hope you don't interview people because what you laid out is full of false assumptions.

New comment by menaerus in "Used La Marzocco machines are coveted by cafe owners and collectors"

menaerus — Fri, 24 Apr 2026 11:55:32 +0000

Do you know what is it that it allows for such a quick warm up? Small boiler? Saturated group? Maybe my comment is more relatable to HX machines then although I don't quite get how is it possible to warm up so quickly - the machine is still a 20kg piece and you can't beat physics with such large thermal mass.

New comment by menaerus in "Used La Marzocco machines are coveted by cafe owners and collectors"

menaerus — Fri, 24 Apr 2026 11:46:32 +0000

So much bs that I don't even want to go further into discussion, sorry. I say this as someone who has made several thousands of espressos on E61 group machine. I'll let you have your own opinion but anyone who has made more than a few espressos will immediately understand if and when the temperature drifted away. Pressure? I've made espressos at 6 bars and 9 bars. Makes literally almost no impact or whatsoever. You're right though that 5 degrees Celsius is probably about the right minimum amount when the espresso starts to change in taste, and there's remarkably many machines which cannot sustain the temperature in shot after shot workloads.

New comment by menaerus in "Used La Marzocco machines are coveted by cafe owners and collectors"

menaerus — Fri, 24 Apr 2026 10:21:37 +0000

The temperature drifting is by far the largest factor in reproducing the espresso shots not the water flow.

New comment by menaerus in "Used La Marzocco machines are coveted by cafe owners and collectors"

menaerus — Fri, 24 Apr 2026 09:54:01 +0000

Do you know what's the difference between the two? Building an espresso machine isn't exactly a science.

New comment by menaerus in "Used La Marzocco machines are coveted by cafe owners and collectors"

menaerus — Fri, 24 Apr 2026 09:46:19 +0000

A good machine will always need time to heat up since the temperature stability, which is very important for getting good espresso shots, correlates with the weight of the device. For most machines this means 30-45 min or so no matter what the manufacturer is saying and in practice this isn't much of a problem once you plug the machine through a smart plug which you can program to turn on the device before you're getting up in the morning.

Secondly, adjusting pressure is almost a completely unnecessary feature so I'm not sure why do you chose to point that out as a major differentiator. 9 bars is just fine. In similar category goes the PID for adjusting the temperature. While on the paper it sounds cool in reality you will not use them 99% of the time. There's many prosumer machines which don't allow you neither of those and are still perfectly fine machines.

New comment by menaerus in "Codex for almost everything"

menaerus — Thu, 16 Apr 2026 21:10:42 +0000

I don't think we are. We will not be able to keep the peace with code production velocity and I anticipate that focus will be moved strongly to testing and validation

New comment by menaerus in "GPT-5.4 Pro solves Erdős Problem #1196"

menaerus — Thu, 16 Apr 2026 07:28:12 +0000

So where's the proof of this exact problem and why exactly did it end up on the list of unsolved problems if it has been already solved?

New comment by menaerus in "jj – the CLI for Jujutsu"

menaerus — Wed, 15 Apr 2026 16:35:15 +0000

Yes, I understand that but what I'm saying is that the problem definition isn't completely clear to me. I'm not saying that there is none, it's just that it may not be obvious at the first read.

New comment by menaerus in "AWS engineer reports PostgreSQL perf halved by Linux 7.0, fix may not be easy"

menaerus — Wed, 15 Apr 2026 07:58:47 +0000

You don't seem to understand the idea that CPU spending time on TLB misses and at the same time seeing no measureable effects in E2E performance because much larger bottleneck is elsewhere can be both valid simultaneously. In database kernels with large and unpredictable workloads, high IO and memory footprint, this is certainly easy to prove.

New comment by menaerus in "Project Glasswing: Securing critical software for the AI era"

menaerus — Wed, 15 Apr 2026 07:53:49 +0000

> Link me the research on the hard engineering tasks they've done on database kernels, I'd love to see it, sounds interesting.

https://www.datadoghq.com/blog/ai/harness-first-agents

https://www.datadoghq.com/blog/ai/fully-autonomous-optimizat...

https://www.datadoghq.com/blog/engineering/self-optimizing-s...

New comment by menaerus in "The future of everything is lies, I guess: Work"

menaerus — Wed, 15 Apr 2026 07:26:26 +0000

> Which regulated professions?

All other engineering (civil, chemistry, mechanical, electrical, ...) and semi-engineering (architecture) disciplines.

New comment by menaerus in "GPT-5.4 Pro solves Erdős Problem #1196"

menaerus — Wed, 15 Apr 2026 06:57:41 +0000

Like what exactly?

New comment by menaerus in "jj – the CLI for Jujutsu"

menaerus — Wed, 15 Apr 2026 06:56:36 +0000

The problem jj is trying to solve is not entirely clear to me but I guess there is enough people who aren't able to find their way with git so for them it probably makes switching to jj more appealing, or at least that's my first impression without going too deep into the documentation.

New comment by menaerus in "Project Glasswing: Securing critical software for the AI era"

menaerus — Fri, 10 Apr 2026 08:05:19 +0000

You're condescending for no valid reason and I will tell you that what you say is not correct. Models superseded "plumbing" tasks and went well into the engineering grounds a generation or two ago already. Evidence is plenty. We see models perfectly capable reasoning about the kernel code yet you're convinced that game engines are somewhat more special. Why? There're plenty of such examples where AI is successfully applied to hard engineering tasks (database kernels), and where it became obvious that the models are almost perfectly capable reasoning about that tbh quite difficult code. I think you should reevaluate your stance and become more humble.

New comment by menaerus in "AWS engineer reports PostgreSQL perf halved by Linux 7.0, fix may not be easy"

menaerus — Wed, 08 Apr 2026 05:59:20 +0000

It is a system-wide toggle in a sense that it requires you to first enable huge-pages, and then set them up, even if you just want to use explicit huge pages from within your code only (madvise, mmap). I wasn't talking about the THP.

When you deploy software all around the globe and not only on your servers that you fully control this becomes problematic. Even in the latter case it is frowned upon by admins/teams if you can't prove the benefit.

Yes, there are workloads where huge-pages do not bring any measurable benefit, I don't understand why would that be questionable? Even if they don't bring the runtime performance down, which they could, extra work and complexity they incur is in a sense not optimal when compared to the baseline of not using huge-pages.

New comment by menaerus in "What happens when a destructor throws"

menaerus — Tue, 07 Apr 2026 06:50:03 +0000

I am an experienced C++ developer, I know what happens in this particular case, but this type of minutiae are only interesting to the developers who have never had an actually hard problem to solve so it's a red flag to me as well. 10 years ago I would have thought differently but today I do not. High performance teams do not care about this stuff.

New comment by menaerus in "AWS engineer reports PostgreSQL perf halved by Linux 7.0, fix may not be easy"

menaerus — Mon, 06 Apr 2026 14:41:21 +0000

You're again assuming that having huge pages turned on always brings the net benefit, which it doesn't. I have at least one example where it didn't bring any observable benefit while at the same time it incurred extra code complexity, server administration overhead, and necessitated extra documentation.

New comment by menaerus in "AWS engineer reports PostgreSQL perf halved by Linux 7.0, fix may not be easy"

menaerus — Mon, 06 Apr 2026 14:35:40 +0000

You said

> Maybe we should, but requiring the use of a new low level facility that was introduced in the 7.0 kernel, to address a regression that exists only in 7.0+, seems not great.

... so that leaves me confused. My understanding is that the regression is triggered with the 7.0+ kernel and can be mitigated with huge pages turned on.

My question therefore was how come this regression hasn't been visible with huge pages turned off with older kernel versions? You say that it was but I can't find this data point.

New comment by menaerus in "AWS engineer reports PostgreSQL perf halved by Linux 7.0, fix may not be easy"

menaerus — Mon, 06 Apr 2026 09:25:59 +0000

Contention doesn't exist in older kernel versions even with huge-pages disabled, no?