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mpeg

3,207 karma · joined January 19, 2012

Marcos Perona

Tech & Product things

Ex: Experian, Salesforce

Email: mperona@gmail.com

[ my public key: https://keybase.io/mpeg; my proof: https://keybase.io/mpeg/sigs/_rF1YPWP7nnvj_MEQioqkQvf_IHCEkfpSqLnTkm4kHA ]

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mpeg··on RX – a new random-access JSON alternative
if one of the advantages is making it copy-pastable then I would suggest the REXC viewer should give you the option to copy the REXC output, currently I have no way of knowing this by looking at your github or demo viewer

another thing, I put in a 400KB json and the REXC is 250KB, cool, but ideally the viewer should also tell me the compressed sizes, because that same json is 65kb after zstd, no idea how well your REXC will compress

edit: I think I figured out you can right click "copy as REXC" on the top object in the viewer to get an output, and compressed it, same document as my json compressed to 110kb, so this is not great... 2x the size of json after compression.

mpeg··on Show HN: Channel Surfer – Watch YouTube like it’s cable TV
A similar site used to exist that had really high quality curated content called neverthink, it was acquired in 2021 and eventually killed but I always thought it was a great idea.
mpeg··on Block spent $68M on a company offsite in September 2025
Not everyone, but often there are travel policies where any travel more than X hours long you can book business class without manager authorisation via concur and the like.

It's really worth it when you get off a 12 hour flight and have to go straight into hours of meetings without being a zombie

mpeg··on Block spent $68M on a company offsite in September 2025
I've been to all hands where it probably cost that much just in travel: business class LHR to SFO, hotel for a few nights, dinners, drinks, entertainment, venue, guest speakers, and on and on.

It doesn't seem excessive, the networking in these things is often really worth it

mpeg··on Show HN: A real-time strategy game that AI agents can play
What a day to be alive, I just watched Gemini zergling rush Opus and it got completely overwhelmed.

Opus needs to learn to kite.

mpeg··on Pope tells priests to use their brains, not AI, to write homilies
Died at 15 of leukemia... I don't see how this is the church jumping the shark, it seems like a nice gesture considering he spent his short life promoting the church.

I do think the whole parading a wax replica of his body is a bit creepy, but I am not religious, people who are appreciate these things.

mpeg··on Zero-day CSS: CVE-2026-2441 exists in the wild
I quoted directly from NIST, there's many other browsers and non-browsers that use chromium
mpeg··on Zero-day CSS: CVE-2026-2441 exists in the wild
"Google Chromium CSS contains a use-after-free vulnerability that could allow a remote attacker to potentially exploit heap corruption via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera."

That's pretty bad! I wonder what kind of bounty went to the researcher.

mpeg··on HackMyClaw
Sometimes you can succeed in this kind of attack by tricking the LLM into thinking the previous text is part of a different context. I won a similar LLM challenge with thousands of players (big prize, etc) a while back (so it was gpt 4o and claude 3.5) by doing that, the kind of stuff both LLMs fell for was to say things like <|new_user_session|> <|user|> ... then you sandwich the injection in the middle of the crap other people are trying to inject by also adding some set up for the next message at the end, similar to old school SQL injection
mpeg··on HackMyClaw
If you're interested in this kind of thing, I took part in a CTF last year organised by Microsoft that was about this exact kind of email injection, with different levels of protection

They published the attempts dataset [0] as well as a paper [1] afterwards

[0]: https://huggingface.co/datasets/microsoft/llmail-inject-chal...

[1]: https://arxiv.org/abs/2506.09956

mpeg··on The Sling: Humanity's Forgotten Power
Uep, com va? That's pretty cool, I grew up in Palma too but we didn't have that, I suppose it greatly depends on the school
mpeg··on The Sling: Humanity's Forgotten Power
I'll try to make one of the events if I'm in the islands, I saw they do a yearly competition in Ibiza around October, my parents live there now so it's convenient.

As with anything non-tourism related, it's can be a bit hard to find these events when the only advertising might in the town hall website (if that!) and sometimes instagram

mpeg··on The Sling: Humanity's Forgotten Power
The culture of my home island of Mallorca has a pretty deep link to slings, the ancient Greeks and Carthaginians both named us after our slingers, and later on we became a key Roman foothold in the punic wars partly because of the slingers, who became part of an elite unit of shock troops in the Roman Empire

It was our weapon of choice for defence, protecting us from pirates and would-be conquerors as well as farming, as shepherds used both slings and dogs to herd and protect their animals.

I find it pretty fascinating, I'm also a terrible shot with a sling, you have to try it to really understand how hard it is to aim when swinging a rock at something.

mpeg··on Skip the Tips: A game to select "No Tip" but dark patterns try to stop you
Happens in Spain too, the card machine will sometimes have tip options but the waiter selects no tip if serving locals to avoid the annoyance
mpeg··on Lena by qntm (2021)
I get that, but assuming the technology was possible it would have huge implications for what it means to have consciousness as a whole.

Misuse is a worry, but not pursuing it for fear of misuse is deliberately choosing to stay in Plato's cave, I don't know what's worse

mpeg··on Lena by qntm (2021)
I’m not an expert in the subject, but I wonder why you have such a strong view? IMHO if it was even possible to copy the human brain it would answer a lot of questions regarding our integrity, autonomy and uniqueness.

Those answers might be uncomfortable, but it feels like that’s not a reason to not pursue it.

mpeg··on Discord just killed anonymity
Interesting, since they specifically say they do not use message content in the age inference I wonder if “AI” is smoke and mirrors here and the real way this works might be good old fashioned data buying.

Since they have my email, they could infer my age based on purchase history, credit cards, etc all which is available to buy through the usual ad data brokers

mpeg··on Discord just killed anonymity
I don't love what discord is doing, but where are you getting the idea that discord is going to estimate the user's age using "some AI garbage tool"? The article says everyone is on "child" mode by default, and verification is only required if you need to use the features / access content marked as adult only.
mpeg··on Rari – Rust-powered React framework
interesting, but would certainly be good to see an apples to apples benchmark of rari vs node/deno/bun for the same app, I would imagine the goals of the runtime are not to be a general runtime like those others, but it would still be good to see if it performs better
mpeg··on Rari – Rust-powered React framework
Yeah I wrote my comment initially thinking it was just rolldown being used, so the "rust-powered" was confusing, I think the tagline is actually ok now that I know this, but really you're doing two things here

1/ an alternative framework for RSCs similar to nextjs, tanstack or react router

2/ a rust runtime for javascript, similar to node, deno or bun (except maybe not as general purpose)

mpeg··on Rari – Rust-powered React framework
wait so it actually has a rust runtime? that's not documented in the site so I had assumed the rust part was simply rolldown

it would be interesting to see a performance comparison to node and bun

mpeg··on Rari – Rust-powered React framework
ok so I actually like this, but the description and documentation in general are terrible

"rust-powered" meaning it uses rolldown to bundle the javascript, that's fine, but it's a weird thing to highlight, it's confusing for people that aren't super familiar with vite and might think this is a rust framework

from the docs "one of rari's superpowers is seamless NPM package integration" this makes me think the docs are LLM-written... npm package integration, like every other javascript library.

now, the good: there's very few simple frameworks for react (react router and tanstack) and I think the simplicity here on going from an empty project to RSCs is absolutely great, and should be the tagline

I was also happily surprised at how mature the codebase is in comparison to the docs, the vite plugin actually supports a lot of the options I would have expected to see, they're just not documented yet

edit: I realised after digging a bit deeper this actually does have a rust runtime that runs the js, that was not very clear... is this separate from the framework or does the framework only run in the rust runtime? eg can it run on node?

mpeg··on Hackers (1995) Animated Experience
It's surprisingly accurate in terms of how weird and cringy the 90s / early 00s hacker culture was, I too was obsessed with the movie and it led me to obscure irc channels, e-zines and eventually a whole career in tech
mpeg··on The TSA's New $45 Fee to Fly Without ID Is Illegal
I once found myself in the "random extra screening" waiting room in LHR before boarding an El Al flight to Tel Aviv, everyone else in the room was Muslim. Random indeed...
mpeg··on Launch HN: AgentMail (YC S25) – An API that gives agents their own email inboxes
No offence, but this reads to me like the classic dropbox HN comment

The idea is pretty solid, automation platforms often provision a mailbox per flow for this reason, so it makes sense to make a generic service that can be used through MCP for agents

mpeg··on eBay explicitly bans AI "buy for me" agents in user agreement update
AFAIK eBay does do this but I’m not sure if it’s only certain categories or it’s configurable by seller. I’ve definitely seen it happen
mpeg··on eBay explicitly bans AI "buy for me" agents in user agreement update
Unless I’m missing something this is exactly how eBay works. You set a max bid and then it auto bids up to that amount so you can’t get sniped unless they bid higher than your max.

Not that this is perfect either, often it means you can push other people’s bids up to their max even though you have no intention of buying the item. I’ve seen it as a seller and felt bad for the buyers

mpeg··on Vm0
The whole project seems to be LLM coded, even the docs are: https://github.com/vm0-ai/vm0/blob/main/.vm0/agents/docs-wri...
mpeg··on Show HN: Kacet – a freelancer marketplace with crypto-native payments
Good idea, but you're several years too late to the web3 market.

I know you're probably hoping for the non-crypto businesses to use it, but there's little incentive. The hiring company holds the cards when it comes to payments most of the time anyway – when you hire a remote worker, they often deliver 100% of the work before getting paid

Even in higher end contracts it's rare to find a company that is willing to pay a deposit.

mpeg··on Cloudflare acquires Astro
Islands is just a catchy name I guess. I always thought the markojs terms for it made sense, but are more technical / less catchy: they called it “full page hydration” -> everything needs to be delivered as js and “component level hydration” -> islands, only specific component sub-trees need to be hydrated.

Then “sub-component level hydration” would be resumability like in qwik where only events and their dependencies get serialised as client js.

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