Sign in

Johannes Weiss

@jweiss.io
689 followers 529 following 200 posts

Computer programmer (github.com/weissi). Distributed systems, ML infrastructure/eval, Swift, previously #SwiftNIO — ♥ snowboarding London, UK

PostsRepliesMedia
Johannes Weiss @jweiss.io · 19/08/2026
Oh no. Tried exactly at 12pm And website was overloaded (Heroku errors). And now everything is fully booked 😳
100
Reposted by Johannes Weiss
852dude @852dude.bsky.social · 13/08/2026
Bro. People are cool as fuck.
274164012328
Johannes Weiss @jweiss.io · 28/07/2026
Booking opens 19 Aug
111
Johannes Weiss @jweiss.io · 28/07/2026
Uh nice one, yes, I'll check that out. Thank you! Are you going too?
100
Johannes Weiss @jweiss.io · 26/07/2026
Totally, what are they even protecting against? You gotta bring ID anyway it seems...
010
Johannes Weiss @jweiss.io · 26/07/2026
But then you probably need cash 😜
110
Reposted by Johannes Weiss
Terence Eden @edent.tel · 26/07/2026
Checked in to Farringdon (Elizabeth Line), 4 Lindsey St, United Kingdom Yeah, fair enough. See on Swarm
A photo of the location.
2182
Johannes Weiss @jweiss.io · 26/07/2026
Also, I'm not buying a #Deutschlandticket to save money (I'm 99% it'll cost more) but to avoid the completely inscrutable and most ridiculous apps ever that they force you to use to buy regular tickets. It's just insane, they want your name, address and an account to buy a single tram ticket there.
100
Johannes Weiss @jweiss.io · 26/07/2026
Buying a #Deutschlandticket is the most German thing ever. You need a passport + selfie style ID verification to buy a _train ticket_. In Britain, I could get a mortgage with less scrutiny and hassle...
Identity check in progress
140
Reposted by Johannes Weiss
Christian Odendahl @codendahl.bsky.social · 24/07/2026
The winning design. 🇪🇺💶
Italian DJs of meme fame on a 20€ note.
311602507
Reposted by Johannes Weiss
Nicolas Fulghum @nicolasfulghum.bsky.social · 09/07/2026
Solar's sharp rise continues. As of April 2026, global solar capacity now exceeds 3 terawatt. 1 gigawatt → 1 terawatt: 20+ years 1 terawatt → 2 terawatt: 33 months 2 terawatt → 3 terawatt: 19 months
412627765
Reposted by Johannes Weiss
Mayor of London, Sadiq Khan @london.gov.uk · 06/07/2026
What a night for England. You could hear London roar in the dark. Quarter-finals, here we come. ⚽
1341036
Johannes Weiss @jweiss.io · 05/07/2026
🤯
000
Reposted by Johannes Weiss
Ketan Joshi @ketanjoshi.co · 01/07/2026
NEW BLOG FOR YOU Google's energy consumption numbers in their new climate report are mind-blowing. 2 years ago they flipped from linear to exponential growth, and their climate impact is blowing out, too. A WILD testament to the obscene bloat and waste of GenAI: ketanjoshi.co/2026/07/01/g...
a chart showing google's rising energy consumption - huge, and rising faster than ever beforea chart showing google's rising energy consumption - huge, and rising faster than ever beforea chart showing google's rising energy consumption - huge, and rising faster than ever beforeGoogle's total energy consumption more than new zealand
4426571469
Reposted by Johannes Weiss
Luc van Donkersgoed @lucvandonkersgoed.com · 23/06/2026
HUGE launch! AWS Lambda MicroVMs - Isolated virtual machines which can run tasks or sessions up to 8 hours. It’s like Lambda and Fargate had a baby, and it inherited the best genes of both. aws-news.com/article/2026...
aws-news.com
Run isolated sandboxes with full lifecycle control: AWS Lambda introduces MicroVMs
AWS Lambda introduces MicroVMs, a new serverless compute primitive powered by Firecracker that provides VM-level isolation, rapid launch/resume, and…
1213
Johannes Weiss @jweiss.io · 13/06/2026
Whoa 😨
010
Reposted by Johannes Weiss
Agam @loopbackdev.bsky.social · 11/06/2026
Vapor 5, alpha - release cut live by @0xtim.bsky.social! 🎉 #swift #vapor
0168
Johannes Weiss @jweiss.io · 08/06/2026
> Apple would have to give any virtual assistant direct access to users’ private data — and the ability to directly control other installed applications — as soon as Siri AI is made available in the EU
310
Johannes Weiss @jweiss.io · 08/06/2026
www.apple.com/newsroom/202...
t.co
https://www.apple.com/newsroom/2026/06/due-to-dma-siri-ai-delayed-in-eu-for-ios-27-and-ipados-27/
210
Johannes Weiss @jweiss.io · 06/06/2026
Talk about few lines and big impact: This fix should finally the dreaded "error: '<dep>': Couldn't check out revision '<sha>'" failures seemingly at random when using SwiftPM. github.com/swiftlang/sw...
github.com
Tolerate dangling remote-tracking refs on checkout by plemarquand · Pull Request #10172 · swiftlang/swift-package-manager
swift package resolve sometimes fails with: error: &#39;&lt;dep&gt;&#39;: Couldn&#39;t check out revision &#39;&lt;sha&gt;&#39;: fatal: bad object refs/remotes/origin/&lt;branch&gt; even thoug...
051
Reposted by Johannes Weiss
Armin Ronacher @mitsuhiko.at · 03/06/2026
In case you are in the camp of “Andrew Tridgell is vibefucking rsync” please read this.l and adjust your priors. medium.com/@tridge60/rs...
medium.com
rsync and outrage
I gave up blogging a long time ago (apart from an occasional thing about ArduPilot), I tend to just write code and hope people find it…
512523
Reposted by Johannes Weiss
Matthew Garrett @mjg59.eicar-test-file.zip · 03/06/2026
Bearer tokens delenda est blog.ammaraskar.com/github-token...
blog.ammaraskar.com
1-Click GitHub Token Stealing via a VSCode Bug
My blog, mostly about programming
2196
Reposted by Johannes Weiss
Swift Language @swift.org · 01/06/2026
When you draw a stroke in Goodnotes on the web, you get the exact same curves and ink flow as on iPad, because it’s literally the same Swift code running on both. ✍️ Goodnotes engineer Yuta Saito shares how they built it with Swift and WebAssembly: www.swift.org/blog/bringin...
05612
Johannes Weiss @jweiss.io · 01/06/2026
Ehhm, this cupboard _hinge_ has a website like some cutting-edge tech product. It's quite hilarious actually: www.grass.eu/en/products/...
grass.eu
Tiomos hinge — GRASS
The Tiomos hinge stands for maximum stability, integrated damping and pure design.
000
Johannes Weiss @jweiss.io · 01/06/2026
Correct?
110
Johannes Weiss @jweiss.io · 27/05/2026
It really looks like Anthropic can become profitable this quarter. I did not expect that last year. I think @simonwillison.net got it right: Claude Code & Codex have found product market fit. Enterprises are paying real money now! bsky.app/profile/jwei... simonwillison.net/2026/May/27/...
simonwillison.net
I think Anthropic and OpenAI have found product-market fit
Anthropic are strongly rumored to be about to have their first profitable quarter. Stories are circulating of companies surprised at how expensive their LLM bills are becoming from usage by …
000
Johannes Weiss @jweiss.io · 24/05/2026
Do you have recommended reading here? My understanding is that the subs are super subsidised indeed. But the actual API calls (which is what many enterprise customers are paying) don't immediately feel very subsidised to me. Are you saying AWS/GOOG are providing Anthropic with subsidised capacity?
010
Johannes Weiss @jweiss.io · 24/05/2026
Hmm, isaiprofitable.com is a bit odd. For Anthropic it shows $33B capex, $6.5B revenue which looks unprofitable. But their own sources say "Anthropic confirmed $30 billion in ARR, up from $9 billion at year-end 2025" (www.saastr.com/anthropic-ju...). So looks like they could break even if desired?
Anthropic $33B capex, $6.5B revenueAnthropic $30B ARR which appears to contradict the $6.5B cumulative revenue. Confused
000
Johannes Weiss @jweiss.io · 02/05/2026
Passkeys/passwords is like IPv6/IPv4 🙈
000
Johannes Weiss @jweiss.io · 02/05/2026
> It feels like applying an enterprise IT/infosec solution to consumers I think this just captures it perfectly!
130
Johannes Weiss @jweiss.io · 02/05/2026
Overall, Passkeys deliver (at best) a small UX improvement over 1pw. But the tradeoff is complexity and you're never quite 100% sure that the passkey you just added will still work in say 5 years. May have switched platforms, may have lost access to that email for the reset if Passkey fails.
100
Johannes Weiss @jweiss.io · 02/05/2026
Agreed. It's really tough competition compared to 1pw: Passwords always work, are conceptually simple and Cmd+\ just works on pretty much all websites. Passkeys are very complex, have quite a few serious restrictions and make some assertions that are difficult to guarantee about your future self.
110
Johannes Weiss @jweiss.io · 02/05/2026
Having thought about this more, I have a more succinct reply: The UX of Passkeys is great when they work. But understanding when they will (not) work is very difficult unless you're intimately familiar with how they work.
020
Johannes Weiss @jweiss.io · 02/05/2026
I guess what I'm trying to say is that Passkeys are mentally taxing (for me). Where I'll want to sign in from later becomes important. And sometimes I get multiple Passkeys, e.g. in work iCloud & in personal 1PW. Makes a fab UX that sometimes works. Passwords w/ 1pw are come close and always work.
020
Johannes Weiss @jweiss.io · 02/05/2026
All totally fair. Passkeys can complicate things in certain in common scenarios: Sharing, backup but also multiple iCloud logins and sign ins in VMs. Trying to ride dual: Passkeys & pws. But I can never quite remember if the Passkey will work. So subconsciously always use password: Cmd+\ and done.
110
Johannes Weiss @jweiss.io · 02/05/2026
The UX is great. But I don't understand when/if/how backups work (depends on 1pw vs iCloud vs ... I believe). And sharing with family etc is difficult. For all its failures, user+password+OTP are conceptually simple. (Yes, security can get murky etc w/o a password manager that checks domains.)
140
Reposted by Johannes Weiss
Terence Eden @edent.tel · 01/05/2026
New blog post: NHS Goes To War Against Open Source shkspr.mobi/blog/2026/05/nhs-goes-t… The NHS is preparing to close nearly all of its Open Source repositories. Throughout my time working for the UK Government - in GDS, NHSX, i.AI, and others - I championed …
shkspr.mobi
NHS Goes To War Against Open Source
The NHS is preparing to close nearly all of its Open Source repositories. Throughout my time working for the UK Government - in GDS, NHSX, i.AI, and others - I championed Open Source. I spoke to dozens of departments about it, wrote guidance still in use today, and briefed Ministers on why it was so important. That's why I'm beyond disappointed at recent moves from NHS England to backtrack on…
46058
Johannes Weiss @jweiss.io · 15/04/2026
Thanks for your work! And pour one for the poor folks working on H1 proxies. It's such a minefield, often not even clear what the correct answer is.
020
Johannes Weiss @jweiss.io · 04/04/2026
I assume this is real-world code not a microbenchmark? Same binary too?
000
Reposted by Johannes Weiss
Swift Language @swift.org · 24/03/2026
Swift 6.3 has landed! 🚀 This release brings community-driven Android support into the official toolchain, along with major improvements to C interoperability, the build system, and embedded Swift. Read more: www.swift.org/blog/swift-6... #AndroidDev #iOSDev
17922
Johannes Weiss @jweiss.io · 22/03/2026
en.wikipedia.org/wiki/The_Inn...
en.wikipedia.org
The Innovator's Dilemma - Wikipedia
130
Reposted by Johannes Weiss
Jan Rosenow @janrosenow.bsky.social · 21/03/2026
Western carmakers are retreating from EVs just as oil hits $100 a barrel. The parallels with Detroit in the 1980s are striking. They ignored fuel-efficient Japanese cars. Now they’re ignoring Chinese EVs. BYD just unveiled 600-mile range and 250 miles of charge in 5 minutes.
722015656
Reposted by Johannes Weiss
Becca Royal-Gordon @beccadax.soincredibly.gay · 27/02/2026
The Swift Performance team isn’t *my* team, but they’re in my hallway. Or in London if you’d prefer. They’re looking for an engineer who’s not afraid of optimizers. jobs.apple.com/en-us/detail...
jobs.apple.com
Swift Compiler Backend Engineer - Jobs - Careers at Apple
Apply for a Swift Compiler Backend Engineer job at Apple. Read about the role and find out if it’s right for you.
22615
Johannes Weiss @jweiss.io · 30/01/2026
😔 feel better!
010
Johannes Weiss @jweiss.io · 30/01/2026
No, I really was not ready for this. Why? What? Please, humans, be better.
0131
Reposted by Johannes Weiss
Jim Waterson @jim.londoncentric.media · 24/01/2026
This is one of the strangest and most screwed-up stories I’ve worked on. www.londoncentric.media/p/tiktok-lon...
londoncentric.media
Who's secretly filming fake TikToks inside Londoners' homes?
We tracked down the viral video account invading people's houses to spread false claims about immigrants.
331150539
Johannes Weiss @jweiss.io · 24/01/2026
Yes, that's right, they do not converge. Currently, I only care for ethernet in one place which works fine. If I need it elsewhere, I'll need to place two extra switches throughout the flat. Essentially daisy chaining the switches.
100
Johannes Weiss @jweiss.io · 24/01/2026
Good day! Inspired by thehftguy.com/2026/01/22/d... I took off my phone sockets to check what's behind. Turns out: CAT 5e! Found three separate cables, previously daisy chained. Ordered RJ45 sockets to replace phone sockets and undid daisy chains. Soon Ethernet in the flat, psyched!
thehftguy.com
Doing Gigabit Ethernet Over My British Phone Wires
Disclaimer: None of this is written by AI, I’m still a real person writing my own blog like its 1999 I finally figured out how to do Gigabit Ethernet over my existing phone wires. Powerline adapter…
130
Johannes Weiss @jweiss.io · 12/01/2026
Quite a few groups seem to be rather successful making many of us believe the opposite. So please note! Some things are getting meaningfully better.
020
Reposted by Johannes Weiss
Swift Language @swift.org · 09/01/2026
FOSDEM, the legendary open source gathering in Brussels, is coming soon, and we'd love to see you there! We've got multiple talks on Swift plus a pre-FOSDEM community meetup. Whether you're a longtime attendee or new to the event, come say hi! 👋 swiftlang.github.io/event-fosdem/ #FOSDEM
swiftlang.github.io
Swift @ FOSDEM 2026
0328