iiinova — where your digital self keeps evolving

René Schwietzke @reneschwietzke.bsky.social · 01/07/2026

Liebe deutsche Politik, ohne großen Wurf, der allen wehtut wird es nix. Wir brauchen eine flexiblen Arbeitsmarkt, weniger Steuern und weniger Steuerregelwerk, aber mehr Kontrolle.

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René Schwietzke @reneschwietzke.bsky.social · 22/06/2026

"Das geht so nicht!" "Das können wir nicht ändern." Bekannte deutsche Sätze.

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René Schwietzke @reneschwietzke.bsky.social · 27/05/2026

I am currently trying to turn my 100 different 1BRC implementations into a JDK release test suite. Who can sell me some time? #youcannotbuytime

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Reposted by René Schwietzke

Wolfgang Weigend @wolfgangweigend.bsky.social · 13/05/2026

The "JFX Adopters Meeting" is a user conference where everyone presents their existing JavaFX application @ZEISS Meditec AG www.zeiss.com/meditec/en/n...

zeiss.com

JFX Adopters Meeting 2026

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René Schwietzke @reneschwietzke.bsky.social · 23/04/2026

Dear #DB, two long distance rides with two transfers each. Both rides on time, from end to end. Small delay from Cologne to Frankfurt but buffered off in Frankfurt. Thank you.

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René Schwietzke @reneschwietzke.bsky.social · 23/04/2026

Just got the information that I have to pay 2 cents less in May per kWh electricity than April. 28.2 Cents. It is a dynamic price and set per month based on energy prices at EEX.

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René Schwietzke @reneschwietzke.bsky.social · 22/04/2026

If you are keen to learn how you can optimize data processing to save CPU and memory, basically money 💰, I invite you to my #JCON2026 talk: "Conquering a Billion Rows with Java Concurrency". I am promising a "Wow, really?". 📅 Wednesday, 22 April 2026, 17:00 CEST 📍 Cinema 6, Cinedom Cologne, JCON

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René Schwietzke @reneschwietzke.bsky.social · 19/04/2026

#jcon2026 Arrived in Cologne and at the Media Park. Just doing what I always do before a talk... sifting it again and again.

Links ein Notebook und rechts ein Kaffee im Glas und eine Stück Kuchen.

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René Schwietzke @reneschwietzke.bsky.social · 19/04/2026

Liebe #DB, heute wird gelobt. Alle Züge pünktlich auf meiner Verbindung. Personal freundlich und Züge sauber. Danke #jena #köln

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René Schwietzke @reneschwietzke.bsky.social · 19/04/2026

And of course, I am still fiddling with my presentation for #jcon. Almost 40 different ways to multithread the #1brc. Most of them are stupid of course, but it is about learning and understanding why, not just saying "Tata". The journey is our goal. #jcon2026

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René Schwietzke @reneschwietzke.bsky.social · 19/04/2026

Starting to in Cologne ... and it is raining cats and dogs.#jcon2026

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René Schwietzke @reneschwietzke.bsky.social · 08/04/2026

For an upcoming customer workshop, I am diving through JFR and all its features. Amazing. I am pretty sure that most Java developers don't know anything about that marvel. Custom events and streaming are extremely useful but who knows that?

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René Schwietzke @reneschwietzke.bsky.social · 23/03/2026

Just asked Gemini to give me the future based on the present.

A medium-long shot captures a bleak, wet city square at dusk, dominated by a grid of large electronic billboards with dystopian advertisements for fictional corporations and technologies. The scene is illuminated by the screen lights reflecting on the pavement and buildings, creating a cool, desaturated color palette. The billboards advertise "CRUDE SECURE™" (a tactical armored vehicle with text about securing resources), "DEFENSE-FLEX™" (a drone for "dynamic conflict management"), and "IMMERSION THERAPY" with a small screen showing a figure in a sensory-deprivation tank, alongside repeating phrases like "SYNTHETIC MEAT SUBSCRIBERS." In the background, small groups of people in dark, layered clothing and face masks gather, looking up at the screens. The architecture consists of grey, multi-story buildings. The depth of field is relatively deep, and the shot is steady and unposed, giving it a documentary feel.

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René Schwietzke @reneschwietzke.bsky.social · 09/03/2026

The new world of development: coming up with concepts, planning and coordinating their execution, and evaluating the results. Three-week sprints are now three-day sprints. Testing is essential, but coding is not. Requirements are critical, but coding is not. I didn't expect that revolution. #AI

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René Schwietzke @reneschwietzke.bsky.social · 09/03/2026

Folks, I took the liberty to use #AI to rip out QuestDB from #JBake and also migrate to JDK 21 minimum. Opinions? It renders jbake.org and my very own blog. Opinions? I would open a PR because QuestDB removal was on the list for a while. github.com/rschwietzke/...

github.com

Build software better, together

GitHub is where people build software. More than 150 million people use GitHub to discover, fork, and contribute to over 420 million projects.

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René Schwietzke @reneschwietzke.bsky.social · 18/02/2026

Just in preparation for #JCON2026. Join my talk on Wed, 22 April 2026 at 17:00 CEST. Conquering a Billion Rows with Modern Java Concurrency schedule.jcon.one/2026/session...

Conquering a Billion Rows with Modern Java Concurrency
Wednesday April 22 17:00-17:45 at Cinema 6, JCON 2026

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René Schwietzke @reneschwietzke.bsky.social · 06/02/2026

Got stuck in Stockholm due to the Berlin airport being shut down for the day. The next attempt is Sunday.

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René Schwietzke @reneschwietzke.bsky.social · 04/02/2026

Greetings to all the great people I met at #jfokus. Thanks to the team of @jfokus.se for bringing us together again. Safe travels and see you in Valhalla.

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René Schwietzke @reneschwietzke.bsky.social · 04/02/2026

Brian Goetz: What's better than solutions? Problems. (Really) #jfokus

Text on white background

What's better than solutions? Problems. (Really)

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René Schwietzke @reneschwietzke.bsky.social · 02/02/2026

Regular developers without being product manager, developer, architect, tester and customer at the same time in one role will be so yesterday in a few months. #jfokus

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René Schwietzke @reneschwietzke.bsky.social · 02/02/2026

Here we go... sitting in the first track #jfokus

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René Schwietzke @reneschwietzke.bsky.social · 26/01/2026

Antigravity is impressive. It sucks that it often strips all comments when refactoring code to fit a new feature. Still experimenting around.

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René Schwietzke @reneschwietzke.bsky.social · 03/01/2026

Dear #ADAC and #Vodafone, it sucks when you name your downloadable invoices with UUIDs and do not include a date or invoice ID. It gets even worse when the UUID changes with each download of the same document. That is so 1998. Happy New Year!

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René Schwietzke @reneschwietzke.bsky.social · 01/01/2026

New year, new password: PassW0rd-2026!

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René Schwietzke @reneschwietzke.bsky.social · 31/12/2025

Happy New Year and Guten Rutsch to all sane people and the Vulcans. Please, discover us!

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René Schwietzke @reneschwietzke.bsky.social · 30/12/2025

AI is to photographers what cars were to coachmen.

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René Schwietzke @reneschwietzke.bsky.social · 28/12/2025

We have to cut subsidies in Germany like hell but I bet that nothing will happen because each subsidy pleases a group of people as an election present.

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Reposted by René Schwietzke

CZEdwards @czedwards.bsky.social · 24/12/2025

I see there’s a post about microplastics going around with a photo of drinking straws, so here is my semi-regular reminder that the 3 biggest sources of microplastics are tires (45%), synthetic clothing particles (35%) and paint (~10%). Lay article attached:

pbs.org

One of the biggest microplastic pollution sources isn’t straws or grocery bags – it’s your tires

Every few years, the tires on your car wear thin and need to be replaced. But where does that lost tire material go? The answer, unfortunately, is often waterways, where the tiny microplastic particle...

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René Schwietzke @reneschwietzke.bsky.social · 18/12/2025

Just got accepted to a Java conference in 2026. My talk will be brand new and build upon my 1BRC presentation. It will try to solve the problem by using all available Java concurrency concepts rather than tuning the code into a C-like hell.

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René Schwietzke @reneschwietzke.bsky.social · 02/12/2025

While converting to virtual threads, I learned something. The carrier thread pool can grow up to 256 native threads. That can happen unexpectedly at any time. You can restrict that. The pool grows when it cannot guarantee thread scheduling. It appears early and unpredictable. No pinning!

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Reposted by René Schwietzke

Nicolai Parlog @nipafx.dev · 26/11/2025

JUnit is undoubtedly one of the most important projects in the #Java ecosystem. And it's 100% free and open! Let me be frank: If we can't get THIS project to the point where a single maintainer can focus on it, then what does that say about our commitment to Free & Open Source Software? 1/3 ⏩

steady.page

Support JUnit

JUnit is maintained by a team of passionate volunteers. This is your chance to give back and support the project!

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René Schwietzke @reneschwietzke.bsky.social · 24/11/2025

Asking CoPilot where its intel comes from: "The information about com.xceptance:xlt: 9.4.0 comes from the official Maven Central Repository. ... Version 9.4.0 is the latest stable release available as of November 2025." No, 9.2.2 is the latest, and there was never a 9.4.0. How drunk are you?

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René Schwietzke @reneschwietzke.bsky.social · 22/11/2025

The outcome of climate conferences does not change anything. Change comes from a technology that makes fossil stuff so expensive that one can only use the new tech. You can only beat the market with the market. That is our sad world.

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René Schwietzke @reneschwietzke.bsky.social · 19/11/2025

Will see you at #jfokus2026. Not as a speaker this time, but as a regular visitor. @devlead.se @jfokus.se

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René Schwietzke @reneschwietzke.bsky.social · 17/11/2025

I find LinkedIn extremely stressful for obvious reasons that I would rather not discuss here. It would simply be impolite.

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René Schwietzke @reneschwietzke.bsky.social · 15/11/2025

For any of my EU followers, I give away two Seoul T-Money public transportation cards. Charged with two to three rides each, ready to be used when you get into the city. Will mail them to you for free. Frees you of the hassle to buy them and get cash to charge them. They are rechargeable!

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René Schwietzke @reneschwietzke.bsky.social · 02/11/2025

Captchas taken to the next level in Korea. I had to screenshot and zoom to see anything.

Captcha of a Korean Navigation App, virtual receipts as base

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Reposted by René Schwietzke

Uncle Joe @sydseter.com · 29/10/2025

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René Schwietzke @reneschwietzke.bsky.social · 11/02/2025

If you missed my 1BRC talk at Jfokus 2025 Stockholm, here you go: youtu.be/dY0ybuNQKFo?... Enjoy and feedback is appreciated.

youtu.be

The First 80% of Reading One Billion Rows Fast Enough by René Schwietzke

YouTube video by Jfokus

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René Schwietzke @reneschwietzke.bsky.social · 05/02/2025

Thanks for rating my #jfokus talk 4.52/5.00. Glad you liked it. Slides for public consumption, sharing, and plundering: training.xceptance.com/java/451-the... The repo: github.com/rschwietzke/...

training.xceptance.com

1BRC - The First 80% of the Journey

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René Schwietzke @reneschwietzke.bsky.social · 05/02/2025

And here you go, the slides to my presentation: training.xceptance.com/java/451-the... Because people asked... they are built using reveal.js. #jfokus

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René Schwietzke @reneschwietzke.bsky.social · 03/02/2025

How fast can you process a billion rows? This talk will guide you through initial tuning steps to achieve a 5x speed improvement. Learn about the JDK, the JVM, and your hardware, and gain insights you can apply to everyday challenges. You'll also learn when not to do that! #jfokus #jfokus2025

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René Schwietzke @reneschwietzke.bsky.social · 31/01/2025

Hello Stockholm, hello #jfokus. Was a pleasant trip.

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René Schwietzke @reneschwietzke.bsky.social · 31/01/2025

Just started to measure all data in my talk again to ensure it is fresh and fits the latest hardware. #jfokus2025

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René Schwietzke @reneschwietzke.bsky.social · 30/01/2025

Before you go on a business trip, you ensure that your girlfriend is not running short of quality bread. Freshly baked sourdough bread.

A rectangular loaf of bread with a light brown, slightly cracked crust sits on a black metal cooling rack, which rests on a wooden countertop. The bread looks rustic and homemade.
In the background, there is a cream-colored wall and a light-colored wooden floor.

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René Schwietzke @reneschwietzke.bsky.social · 30/01/2025

In case you make it to JFokus 2025 Stockholm, I would be delighted to see you at my talk "The First 80% of Reading One Billion Rows Fast Enough". jfokus.se/talks/2178

jfokus.se

Jfokus

Jfokus is all about developers! Check out the conference: https://www.jfokus.se

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