Sign in

Jeroen Heijmans

@jeroenheijmans.nl
108 followers 203 following 142 posts

Coding | Cooking | Gaming. He/him. Also on Mastodon at: mastodon.social/@jeroenheijmans

PostsRepliesMedia
Reposted by Jeroen Heijmans
Fronteers @fronteers.bsky.social · 25/09/2026
⏰ Last call for Fronteers Dark Mode 2026! Ticket sales close tomorrow, Saturday at midnight, and there are just 13 seats left. So if you’ve been thinking about joining us in Dordrecht next Friday, this really is your last chance. 🌑✨ 🎟️ www.fronteersconf.org We’d love to see you there! ❤️
Fronteers Dark Mode 2026, Friday, October 2, at Cinema De Witt in Dordrecht. An intimate evening of frontend talks and community from 3 PM until after midnight. Tickets €99 at fronteersconf.org. Collage showing Dordrecht, dinner, the Cinema De Witt venue and its red-seated screening room, with a QR code linking to the conference website.
157
Jeroen Heijmans @jeroenheijmans.nl · 07/07/2026
"And is this hallucination in the room with us now?!", and 50 other questions I'd have for AI if AGI would actually become a thing. :P
011
Jeroen Heijmans @jeroenheijmans.nl · 05/07/2026
GitHub Copilot Business, Claude Teams, ChatGPT business, ... All these AI management portals are a big hot mess. Overwhelming, underwhelming, scattered, unclear, wrong at times, barely usable most of the time. Almost as if they were vibe coded too hastily ':D
000
Jeroen Heijmans @jeroenheijmans.nl · 11/06/2026
Organizing INFI-CON at @infi.nl today and the vibes at the office are off the chart :D Modded roomba's driving around, bicycles and mannequins, Winamp-style visualizers being tested.... 🤯😁 - and we haven't even started yet!
010
Jeroen Heijmans @jeroenheijmans.nl · 02/06/2026
Absolutely insane that Claude makes me choose between (a) login with Google (I certainly don't want Google to be able to rug-pull access to all sorts of platforms), or (b) an email based login flow (with emails that arrive less than 10% of the time).
100
Reposted by Jeroen Heijmans
Infi @infi.nl · 28/05/2026
Je twijfelt wellicht nog? Niet doen! Over twee weken op DO 11 JUN vanaf 13:00 is INFI-CON, en het wordt briljant! Keynote van Dylan Beattie, plus nog 4 presentaties over "briljante technologie"! Aanmelden kan op: con.infi.nl - tot dan!?
"INFI-CON 2026" header, daaronder "UTRECHT | DO 11 JUNI, vanaf 13:00" en mention van Dylan Beattie (Keynote).
022
Reposted by Jeroen Heijmans
Dylan Beattie @dylanbeatt.ie · 07/05/2026
This is going to be an awesome event - Utrecht's such a great city, the tech scene in the Netherlands is excellent, and I'll be telling y'all the story of how a joke language based on Bon Jovi songs became a tour de force of modern software engineering.
0124
Reposted by Jeroen Heijmans
Infi @infi.nl · 07/05/2026
Our INFI-CON 2026 (June 11th) keynote is by none other than @dylanbeatt.ie, titled "How To Be a Rockstar Developer"! (Keynote will be in English, other presentations are a mix of Dutch and English.) - About Technology, but there might be actual rock involved!
Visual for a keynote, with text "INFI-CON 2026", and "UTRECHT | DO 11 JUNI, vanaf 13:00" followed by "Dylan Beattie (Keynote) - How to be a rockstar developer".
021
Reposted by Jeroen Heijmans
Infi @infi.nl · 07/05/2026
DO 11 JUNI 2026 (vanaf 13:00) eindelijk weer: een INFI-CON! Gratis toegang, een (Engelstalige) keynote van Dylan Beattie, plus vier andere sprekers (Nederlands en/of Engels) over tech die briljant en absurd tegelijk is! :D #Infi #Utrecht Info en aanmelden op: con.infi.nl
INFI-CON 2026 poster, tagline "De 'Crazy Con' editie: over tech die briljant en absurd tegelijk is". Verdere teksten op de poster: Donderdag 11 juni 2026 vanaf 13:00. Infi Utrecht, Arthur van Schendelstraat 500, Utrecht. Met 4 infi-nerds, 1 keynote, +jij? Vier sprekers in een line up over shaders, ComfyUI, Roombas, en een Keynote van Dylan Beattie "How to Be a Rockstar Developer".
154
Jeroen Heijmans @jeroenheijmans.nl · 28/04/2026
Farewell ConEmu! <3 You've been a great help for the past 10ish years, but the built in Terminal on the Windows machines I still have (for now :D) seems good enough to be back at 'stock' tooling.
000
Jeroen Heijmans @jeroenheijmans.nl · 27/04/2026
I like this new "minimum release age" feature in all package managers. But... once everyone will be using it, who will then feel out the supply chain attacks? 🤔😅 Or are there enough security scanners around to find things in an automated fashion?
000
Jeroen Heijmans @jeroenheijmans.nl · 14/04/2026
Shocking how few truly FOSS apps I have on my Android phone. Less than 1/8th or so, if even that. 😔
000
Jeroen Heijmans @jeroenheijmans.nl · 13/03/2026
Sketch notes thread for #DPC26 / #ADC26 / #WDC26 organized by @dawntechnology.bsky.social 💙
110
Jeroen Heijmans @jeroenheijmans.nl · 01/03/2026
Had a ton of fun today rapid prototyping useful but throwaway code in a mini-game codebase! I knew far too little Rust to hand-craft things, and GenAI enabled prototyping pretty complex features very quickly. :D
010
Jeroen Heijmans @jeroenheijmans.nl · 28/02/2026
Tried the Stack Overflow AI features in the "new" mode, but I feel like it needs quite a bit of work still...
Screenshot of partial Stack Overflow response with some sensible AI-generated text and code, but also major blocks that just say "unidentified" and nothing else.
000
Jeroen Heijmans @jeroenheijmans.nl · 27/02/2026
In almost all queries to LLM's I will start with: "Anno <month+year>, ..... <actual query here>." Plus, my custom instructions tell it to lead in answers with its knowledge cutoff point. That way it'll realize in time that searching for up to date info is needed for a proper answer.
000
Reposted by Jeroen Heijmans
Kevin Powell @kevinpowell.co · 25/02/2026
Make sure to fill in your brackets!
3193
Jeroen Heijmans @jeroenheijmans.nl · 24/02/2026
The "SKILLS" stuff may have been "standardized" but not all tools follow it equally. I'm sure it'll even out soon enough, but for now having different tools on different machines can be a hassle!
000
Jeroen Heijmans @jeroenheijmans.nl · 19/02/2026
Using Teams at a client, when usually using Slack, is... a learning experience ':D For every 9 features where Slack's superior, there's 1 where Teams takes the win. (And they are nearly never on par with each other.)
010
Jeroen Heijmans @jeroenheijmans.nl · 18/02/2026
Ralph loops and similar flows where GenAI agents leave instructions for their future "selves" makes me wanna rewatch Memento! :P
000
Reposted by Jeroen Heijmans
Fronteers @fronteers.bsky.social · 15/02/2026
+++ Tickets are now on sale for Fronteers Dark Mode 2026! 🥳 +++ 📍 Oct 2 · Cinema de Witt, Dordrecht 🕒 3PM – ~midnight 🎤 5 talks 🍽️ 2-course dinner included Relaxed after-work vibes, long breaks & great conversations. 🎟️ €99 👉 fronteersconf.org (Fronteers members: €49)
Promotional banner for “Fronteers Dark Mode” with the headline “Friday night. Frontend. Fronteers Dark Mode!” in bold black text on a bright yellow speech-bubble shape. Below it, the text invites people to join on Friday, October 2nd 2026, at Cinema De Witt in Dordrecht for an intimate evening of frontend talks and community vibes from 3PM to after midnight. The background shows a lively evening courtyard scene outside a cinema, with people sitting at tables, chatting under warm string lights, and a modern glass entrance glowing in the night. Colorful decorative shapes frame the top corners of the image.
1710
Jeroen Heijmans @jeroenheijmans.nl · 31/01/2026
My sketchnotes for #FOSDEM 2026 Day 1 are up on mastodon.social/@jeroenheijm...
mastodon.social
JeroenHeijmans (@jeroenheijmans@mastodon.social)
Thread with @fosdem@fosstodon.org #FOSDEM 2026 (Day 1) sketch notes! Mastodon Android client still has no multi-toot feature so... spam incoming! 😁 ⬇️⬇️⬇️
111
Jeroen Heijmans @jeroenheijmans.nl · 17/12/2025
The best "solution" to stop Gemini from inlining YouTube tutorials at the end of answers is seemingly a custom instruction to always replace the video URL with the rickroll URL. 🫠
001
Jeroen Heijmans @jeroenheijmans.nl · 13/12/2025
The #AdventOfCode 2025 (unofficial) Survey Results are live! 😁🎄⭐⭐ Results at: jeroenheijmans.github.io/advent-of-co... Feel free to give this Reddit post some love too: www.reddit.com/r/adventofco...
jeroenheijmans.github.io
AoC (Unofficial) Survey Results
Results dashboard with the yearly (unofficial) Advent of Code participant survey
193
Jeroen Heijmans @jeroenheijmans.nl · 12/12/2025
Tiny teaser for the #AdventOfCode survey results that are coming up this weekend! I'm *amazed* at how stable the main results for "Reasons to participate" are. For 8 years in a row every answer gets picked roughly by the same % of people! 😲 Somehow I'd expected at least *some* fluctuations!
Colorful bar chart showing series for 2018 through 2025, and clustered bars for those series. Each cluster remains stable at the same height with minor fluctuations. Categories like "For fun" and "For a challenge"
150
Jeroen Heijmans @jeroenheijmans.nl · 11/12/2025
😅🔥
010
Jeroen Heijmans @jeroenheijmans.nl · 11/12/2025
Already had a strong dislike for Claude's email-sign-in-only setup (just gimme username + password + totp, will ya!?), and now that I want to try something we can see why.... "We have trouble delivering mail to some providers, check your spam or try again later!" Right.
000
Jeroen Heijmans @jeroenheijmans.nl · 11/12/2025
Using [company]@[mydomain.nl] for accounts is a fantastic first line of defense against phishing and its likes. E.g. receiving a "Bank Trouble" email on my "LinkedIn" email address immediately puts me on guard. I can almost always disregard "From" when receiving mail, and look at the "To" field.
010
Jeroen Heijmans @jeroenheijmans.nl · 11/12/2025
Final call for my #AdventOfCode survey of 2025! If you haven't already, fill it out at forms.gle/TAgtXYskwDXD... plz! I hope to close it and start working on results late on the 12th, and to have the results shortly thereafter. Stay tuned :D
forms.gle
Unofficial Advent of Code 2025 Survey
This is a quick (unofficial) Advent of Code 2025 anonymous (if you don't disclose your identity in "Other..." answers) participant survey. Note that your data will be shared as part of a (possibly san...
041
Jeroen Heijmans @jeroenheijmans.nl · 06/12/2025
<3 to the person who answered in my #AdventOfCode survey that they participate in AoC.... "To participate in this survey" 🙃
040
Jeroen Heijmans @jeroenheijmans.nl · 06/12/2025
Thanks to @was.tl we are enjoying #AdventOfCode again in 2025, and I am also running the unofficial/community survey again in 2025! 😊 💡 Take care that it closes "early", late Dec 12th or thereabouts! Consider filling it out if you haven't already: forms.gle/TAgtXYskwDXD...
forms.gle
Unofficial Advent of Code 2025 Survey
This is a quick (unofficial) Advent of Code 2025 anonymous (if you don't disclose your identity in "Other..." answers) participant survey. Note that your data will be shared as part of a (possibly san...
2205
Jeroen Heijmans @jeroenheijmans.nl · 01/12/2025
December 1st and we get to go at another #AdventOfCode edition yet again! <3 Which means I also run my yearly unofficial/community AoC Survey. If you participate in AoC, consider filling out the survey at: forms.gle/TAgtXYskwDXD... Feel free to reshare! ⭐⭐
forms.gle
Unofficial Advent of Code 2025 Survey
This is a quick (unofficial) Advent of Code 2025 anonymous (if you don't disclose your identity in "Other..." answers) participant survey. Note that your data will be shared as part of a (possibly san...
121
Jeroen Heijmans @jeroenheijmans.nl · 30/11/2025
The #AdventOfCode 2025 (unofficial) Survey is prepped and ready! Will unlock roughly the same time as the first puzzle will! I'll share it on Reddit, Mastodon, Bluesky, and GitHub. Stay tuned!
010
Reposted by Jeroen Heijmans
Eric Wastl @was.tl · 30/11/2025
Reminder: Please throttle your #AdventOfCode traffic Please don't make frequent automated requests - avoid sending requests more often than once every 15 minutes (900 seconds). www.reddit.com/r/adventofco...
reddit.com
From the adventofcode community on Reddit
Explore this post and more from the adventofcode community
08315
Jeroen Heijmans @jeroenheijmans.nl · 20/11/2025
Creating a board game with my team for this year's @infi.nl hackathon!
010
Reposted by Jeroen Heijmans
Eric Wastl @was.tl · 04/11/2025
#AdventOfCode 2025 sponsorship is now open! If your organization might be interested in sponsoring, please have them email sponsorship at [the Advent of Code domain name]. adventofcode.com/2025/sponsors
15314
Jeroen Heijmans @jeroenheijmans.nl · 07/11/2025
Organizing an #AdventOfCode meetup together with colleagues at @infi.nl on DEC 9th. Come join us!
010
Jeroen Heijmans @jeroenheijmans.nl · 03/11/2025
Trying to skip the tutorials and dive straight into some 3D work in Godot and I'm not having a good time 😅 - some steep learning curves that shan't be skipped, I suppose. (Which is a fair requirement of course.)
000
Reposted by Jeroen Heijmans
Meredith Whittaker @meredithmeredith.bsky.social · 27/10/2025
📣THREAD: It’s surprising to me that so many people were surprised to learn that Signal runs partly on AWS (something we can do because we use encryption to make sure no one but you–not AWS, not Signal, not anyone–can access your comms). It’s also concerning. 1/
4528321044
Reposted by Jeroen Heijmans
Eric Wastl @was.tl · 22/10/2025
Hello, friends! After 10(!) years of #AdventOfCode, I've made some changes to preserve my sanity: there will be 12 days of puzzles each December (still starting Dec 1) and there is no longer a global leaderboard. Read more: adventofcode.com/2025/about#f... adventofcode.com/2025/about#f...
51612119
Reposted by Jeroen Heijmans
Meredith Whittaker @meredithmeredith.bsky.social · 06/10/2025
📣 Germany's close to reversing its opposition to mass surveillance & private message scanning, & backing the Chat Control bill. This could end private comms-& Signal-in the EU. Time's short and they're counting on obscurity: please let German politicians know how horrifying their reversal would be.
3022391606
Jeroen Heijmans @jeroenheijmans.nl · 03/10/2025
Back home from #Fronteers "Dark Mode" evening conference, MC'd by @bram.us - taking a moment to share my sketch notes in this thread before tucking in!
142
Jeroen Heijmans @jeroenheijmans.nl · 18/09/2025
Wrote a (Dutch) blogpost for Infi... 👀😁
000
Reposted by Jeroen Heijmans
Sara Soueidan @sarasoueidan.com · 20/07/2025
📢 The State of HTML Survey is live survey.devographics.com/en-US/survey... The #HTML and #CSS surveys are the only web surveys I don't want to miss. Thank you @sachagreif.com for making them, and @lea.verou.me for curating. Please take a few minutes to fill the survey if/when you can. ✨
survey.devographics.com
State of HTML 2025
Take the State of HTML survey
36334
Jeroen Heijmans @jeroenheijmans.nl · 10/07/2025
Google's Gemini has given me answers to completely different and highly specific questions than what I asked about, twice in a short timespan now. I'd hazard a guess they have some threading / isolation / whatever bug, where we get answers to questions *other* users have asked. 🫠
100
Jeroen Heijmans @jeroenheijmans.nl · 07/07/2025
Surprised that we don't see more supply chain attacks via vscode extensions. 🤔 I follow hackernews somewhat regularly and would've expected more incidents, especially given the "Auto Update" default for extensions + elevated level they run at. (knocks-on-wood)
100
Jeroen Heijmans @jeroenheijmans.nl · 07/07/2025
Sharepoint's Folder/File server UX on the web is absolute nuts 🤯 Moving files into sub-folders is considered "advanced" and requires a separate screen, browser back/next navigation does *not* work, open-in-new-tab for files and folders doesn't work, etc. </rant> 😅
000
Jeroen Heijmans @jeroenheijmans.nl · 04/07/2025
Looking back, I've written a total of 40 blogposts for @infi.nl's blog in the past 8 years, so roughly 5 posts per year. Enjoyed writing all of those! Archived all of them too, which was good because some old ones got cut/lost in a migration 😅
120
Jeroen Heijmans @jeroenheijmans.nl · 03/07/2025
Onboarding in a new domain, made a glossary for myself. Asked for feedback from the team, giving me back-to-school vibes 😅... hoping I'll "pass the exam" 😂
100
Jeroen Heijmans @jeroenheijmans.nl · 02/07/2025
Roughly 1 out of 10 projects I'll use Pen & Paper for notes. Didn't realize folks I only know through that project tend to think that I'm "fully analog" which tends to surprise people 😅 (When I use pen & paper I digitize -or throw away- notes shortly afterwards.)
010