Roy van Rijn
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royvanrijn.com
Roy van Rijn
@royvanrijn.com
Director of OpenValue Rotterdam, is a @Java_Champions, founder of Rotterdam JUG, public speaking: Java, AI, math, algorithms
Reposted by Roy van Rijn
MELBOURNE, Australia, December 4th - #FashionTech Meet-Up, come join! RSVP through the site (free) #Robotics #SmartTextiles #ML #Sensors

events.humanitix.com/fashiontech-...

Melbourne Dec 1 - 6
Brisbane Dec 6 - 10
Sydney Dec 10 - 13
Canberra Dec 13 - 15
NZ Dec 15 - Jan 5
FashionTech Meetup with special guest Anouk Wipprecht
Anouk Wipprecht is a Dutch designer/engineer working at the cutting edge of FashionTech; where couture meets robotics, AI, and interactive design. Her creations
events.humanitix.com
November 5, 2025 at 8:09 AM
Really looking forward to see everybody at J-Fall's speakers dinner tonight, who's going to be there?
November 5, 2025 at 8:05 AM
The em-dash is a clear indicator text was generated by AI.

What is the em-dash of generated code?
October 30, 2025 at 6:54 PM
Periodic reminder…
October 30, 2025 at 12:14 PM
Respect to the man in the ice cream van! 🚐 🍦
October 29, 2025 at 8:39 PM
Reposted by Roy van Rijn
Next up we’re learning how to use Agentic AI/MCP using Kotlin with David Stibbe
October 28, 2025 at 7:01 PM
Reposted by Roy van Rijn
First speaker of the day is @wbauweraerts.bsky.social on moving from fragile to fearless tests.

Perfect breakdown on how testing should be used to be able to test and deploy with confidence 💪🏼
October 28, 2025 at 5:35 PM
Drinks with @openvalue.eu at #Devoxx (as usual)...

See you there?
October 6, 2025 at 2:07 PM
If you don’t pay for YouTube, you’ll get some unskippable ads…

Sooooo if a software conference doesn’t pay their speakers, should they be allowed to sell in-talk ad-segments? 😂

“This talk is made possible by Squarespace/NordVPN/Raid Shadow Legends/Brilliant”
October 3, 2025 at 7:29 AM
I'm once again looking for awesome speakers and topics for upcoming @rotterdamjug.bsky.social meetup(s).

The next one is probably going to be in the week of 27 - 31 October... 👻 🎃

If you're interested, DM me!
September 8, 2025 at 8:15 AM
☕️ Caffeine is inevitable.

Numerous plants across the world evolved producing caffeine independently. To poison bugs, sabotage rivals, and even hack bees’ memories...
September 8, 2025 at 7:41 AM
Seen this series (in progress) @gunnarmorling.dev ?

youtu.be/n-YK3B4_xPA?...
Solving Java’s 1 Billion Row Challenge (Ep. 1) | With @caseymuratori
YouTube video by Marco Codes
youtu.be
September 5, 2025 at 11:47 AM
Reposted by Roy van Rijn
Join @royvanrijn.com at #YOW25, where he shows how Java can fly in his talk "Pushing Java to the Limits: Processing a Billion Rows in Under 2 Seconds"

MEL 4-5 Dec | BNE 8-9 Dec | SYD 11-12 Dec yowcon.com
August 25, 2025 at 1:49 AM
Roy, it looks like there is a typo in your resume, it says Scumm Master instead of Scrum Master.

...

Nope.
August 12, 2025 at 11:41 AM
Reposted by Roy van Rijn
1 billion rows<2s. 🚀
@royvanrijn.com joins #YOW25 & shows how Java can fly in his talk "Pushing Java to the Limits: Processing a Billion Rows in Under 2 Seconds"

MEL 4-5 Dec | BNE 8-9 Dec | SYD 11-12 Dec yowcon.com
July 30, 2025 at 11:44 PM
Imagine travelling to one of the poorest countries in the world, 🇲🇼 Malawi, and being welcomed with more kindness and warmth than you'd expect anywhere.

That’s exactly what happened to Rob, a friend of mine.

Read his story here:
www.100procentmalawi.org/founding
Founding
My journey through East Africa: I had been to Africa several times and each time I was struck by the genuine friendliness and cheerfulness of the people I met. What struck me most was how warm and h...
www.100procentmalawi.org
June 25, 2025 at 7:45 AM
He made Windows (tm)?
June 19, 2025 at 6:12 PM
Found one, this algorithm is easy.
June 5, 2025 at 8:27 PM
Best slogan I could come up with for a software company from Rotterdam 😅

Get your @openvalue.eu Rotterdam laptop sticker at @joyofcoding.bsky.social later this month 👍🏼
June 4, 2025 at 9:24 AM
Reposted by Roy van Rijn
Join me tomorrow at @rotterdamjug.bsky.social (Java User Group) with
@andresalmiray.com!

Andres will talk about deploying to production with confidence and I'll share how to be more productive when working with multicultural teams.

www.meetup.com/rotterdamjug...
Deploying with Confidence & Working across Cultures, Tue, Jun 3, 2025, 5:30 PM | Meetup
Join us for an evening of tech insights and real-world stories! **Andres Almiray** will share how to deploy to production with confidence, while **Rijo Sam** explores lesso
www.meetup.com
June 2, 2025 at 8:23 AM
Israel has its Iron Dome.

America will get a Golden Dome.

I propose a similar project for the Netherlands, we can call it… the Thunder Dome.
May 26, 2025 at 5:41 PM
Last week I tried surimi, didn’t like it, it tastes like crab.
May 25, 2025 at 6:09 PM
This is by far the best and scariest AI-generated creation I’ve come across.

(made with Veo 3)
May 22, 2025 at 10:23 PM
A shift is happening in our family's € 1000,- investment challenge...

I've started to make a comeback, almost back into the green, my partner finally started to drop a little, and kid 1 is in a free fall 😅 📉
May 22, 2025 at 12:59 PM