Peter Ullrich
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peterullrich.com
Peter Ullrich
@peterullrich.com
#ElixirLang Developer. Blogger. Loves: Dad Jokes. Sport. Africa.

Founder: IndieCourses.com + LetterToYourself.com
Learn Elixir: runelixir.com
Blog: peterullrich.com
Courses: indiecourses.com/directory
Reposted by Peter Ullrich
Soon in MDEx ➡️ Phoenix Components!

Yes, MDEx will support embedding HEEx templates inside Markdown. Components and Elixir empressions.

hex.pm/packages/mdex

#MyElixirStatus
November 26, 2025 at 2:14 PM
Reposted by Peter Ullrich
My "Library Client/Server Symmetry" talk from AlchemyConf 2025 is out! If you're interested in building & maintaining libraries and HTTP, I'm really curious about your feedback! #MyElixirStatus content.subvisual.com/talk-roundta...
Wojtek Mach // Library Client/Server Simmetry - Content Hub Blog
content.subvisual.com
November 26, 2025 at 9:27 AM
Had a great time implementing a UDP-based variation of traceroute today. Interestingly, it sends a UDP packet, but listens for an ICMP reply!

Also, found out that every open ICMP socket will receive every incoming ICMP packet which is bad for parallelism.

github.com/PJUllrich/tr...
GitHub - PJUllrich/traceroute: A traceroute implementation in Elixir
A traceroute implementation in Elixir. Contribute to PJUllrich/traceroute development by creating an account on GitHub.
github.com
November 24, 2025 at 4:09 PM
Reposted by Peter Ullrich
It is awesome to see my code inspire others to do other awesome things.

BTW currently I am working on completely bonkers concept that can open completely new interesting scope for others, and I think it will be really nice for stuff like @nerves-project.org.
I finished my little "Rebuild Traceroute in Elixir using ICMP" project and the results are pretty close to the original traceroute output!

I'll write up a blog post about this next week, but if you want to peek at the code already, it's here:

github.com/PJUllrich/Pe...
November 24, 2025 at 10:08 AM
The Dutch government has ran an info campaign urging its citizens to be prepared for 72h of blackouts and we took it to heart. Obviously the highest priority would be to keep the coffee flowing so we bought a gas burner and a mokka. Prepping can be quite fun actually!
November 23, 2025 at 11:34 AM
Reposted by Peter Ullrich
testing it myself and can confirm, it has no guardrails whatsoever
November 23, 2025 at 2:48 AM
Reposted by Peter Ullrich
Twitter pays people based on engagement (views, retweets, comments, etc). It appears that many MAGA accounts are based abroad and they use AI technology to generate low-effort rage bait.

My guess is that this will get worse as AI tech improves. For instance, fake videos of minorities doing crime.
November 23, 2025 at 9:23 AM
I finished my little "Rebuild Traceroute in Elixir using ICMP" project and the results are pretty close to the original traceroute output!

I'll write up a blog post about this next week, but if you want to peek at the code already, it's here:

github.com/PJUllrich/Pe...
November 22, 2025 at 2:51 PM
Reposted by Peter Ullrich
Goto Mix docs example app:
NOT a to-do app.
But a distributed key value store.
The primagen approves 😁
#elixirlang

youtube.com/shorts/7zMUh...
Elixir Community don't mess around
YouTube video by ThePrimeTime
youtube.com
November 21, 2025 at 7:02 PM
Reposted by Peter Ullrich
Bump phoenix to debian trixie
#elixirlang

phoenix generator diff:
github.com/phoenixframe...
November 21, 2025 at 11:44 AM
Reposted by Peter Ullrich
Made a little library inspired by cloudevents-ex. It wraps avrora and it makes it super simple to create maps following the cloud events spec and encode/decode them in Avro. #ElixirLang

github.com/giusdp/pulsa...
November 21, 2025 at 2:48 PM
I have to give a 5min lightning talk at a local meetup in 1h. Quick, what Elixir-related topic should I talk about?
November 20, 2025 at 4:56 PM
Oh, every visitor opened at least one LiveView socket, so this is how it looks like to have 10k LiveView sessions on a 8$/mo droplet 😄 (not simultaneously though)
Oh nice! My Postgres WAL post got the attention of HackerNews! I didn't even notice it but I should probably increase my tiny $8/mo droplet's memory :D
November 20, 2025 at 1:36 PM
Great interview about @tigerbeetle.com, a custom-built database for financial transactions. Don't watch it if you actually have stuff to do :D

www.youtube.com/watch?v=9oyh...
A million transactions per second: building TigerBeetle with Joran Greef
YouTube video by The Database School Podcast
www.youtube.com
November 20, 2025 at 11:55 AM
Oh nice! My Postgres WAL post got the attention of HackerNews! I didn't even notice it but I should probably increase my tiny $8/mo droplet's memory :D
November 20, 2025 at 9:52 AM
Reposted by Peter Ullrich
From the people who brought you the financial crisis, Theranos, and Juicero: say hello to data center financial engineering!
I'm pretty nervous about this ending badly, but everyone's dug in because AI is the only pulse in the economy.
prospect.org/2025/11/19/a...
The AI Bubble Is Bigger Than You Think - The American Prospect
It’s not just OpenAI that looks overhyped. There’s a whole mountain of sketchy financial engineering underneath.
prospect.org
November 19, 2025 at 2:37 PM
Since my blog is hosted on Digital Ocean and doesn't use Cloudflare's proxy, you can still read it while everything else is down!

peterullrich.com
Peter Ullrich - Elixir Developer and Educator
Personal blog of Peter Ullrich, a Senior Elixir Engineer, Freelancer, Educator, and Entrepreneur from The Netherlands.
peterullrich.com
November 18, 2025 at 2:40 PM
Oh fun. Cloudflare is down. And I wondered already why my CI is failing (it can't download ObanPro which is cached by them)
November 18, 2025 at 1:24 PM
Reposted by Peter Ullrich
And I thought Erlang stood for ERicsson LANGuage 😬
November 18, 2025 at 8:45 AM
Reposted by Peter Ullrich
Tau5 just made its first sound.

It was the Amen Break... followed immediately by me shouting for joy and leaping around the room.
November 17, 2025 at 5:00 PM
Small FYI if you use Expert in Zed:

Please update to the v0.2.4 since it includes my fixes for two blocking bugs.
November 17, 2025 at 10:02 AM
Reposted by Peter Ullrich
Hey Elixir friends! :)
We need help completing Elixir's browser runtime by porting some Erlang functions to JavaScript.
No Erlang knowledge required. Each function unlocks multiple Elixir stdlib functions!
More here: hologram.page/blog/elixir-...

#Hologram #Elixir #ElixirLang #BEAM #WebDev
November 16, 2025 at 1:09 AM
Reposted by Peter Ullrich
I updated the SuperSonic example to include synths, samples and FX and a fun playful interface.

SuperSonic is my port of SuperCollider’s extremely powerful scsynth engine to Web AudioWorklets so it can run in the browser.

Play with it here:

sonic-pi.net/supersonic/d...
November 15, 2025 at 2:25 PM
Reposted by Peter Ullrich
Have you answered the survey already?

#ElixirLang
We didn’t expect such a big response this year, and we love to see it. If you haven’t filled it in yet, you now have time until November 18.
💜 elixir-survey.typeform.com/2025-edition

#elixir #elixirlang #myelixirstatus #elixirprogramming
November 14, 2025 at 10:56 AM
Reposted by Peter Ullrich
PSA: If your expert LSP refuses to properly work with Elixir 1.19, try unsetting MIX_OS_DEPS_COMPILE_PARTITION_COUNT for now.

github.com/elixir-lang/...
Engine Build: MIX_OS_DEPS_COMPILE_PARTITION_COUNT being set causes engine build fail · Issue #211 · elixir-lang/expert
After upgrading to 1.19 I wasn't able to get expert to run anymore. While there where a few blockers coinciding (like the --stdio stuff), after going through all the troubleshooting clearing the lo...
github.com
November 13, 2025 at 7:20 AM