Andrus Adamchik @andrus.adamchik.org · 09/03/2026Incidentally, Bootique that was conceived 10 years ago is rather Claude-friendly out of the box. With "-h" describing in plain text how to run and "-H" - how to configure an app. The idea back then was to make each app self-explanatory in runtime. Little did we know 🙂 010
Andrus Adamchik @andrus.adamchik.org · 28/02/2026Talking of fast data loaders, we replaced Apache "commons-csv" with hand-coded CSV parser in DFLib, and suddenly all my log processing is 6x faster! (about 4.7s for an 8GB CSV vs 29s before) 🚀 And we have a chance to make it 12x or better based on early parallelization POCs 010
Andrus Adamchik @andrus.adamchik.org · 28/02/2026Oh nice. We just finished a set of Parquet optimizations in DFLib based on parquet-java. Looks like our reader is due for another facelift 020
Andrus Adamchik @andrus.adamchik.org · 22/02/2026Just hacked a simple table viewer for one of the company datasets with Tamboui / DFLib / Bootique. Looks promising to build internal business automation on the cheap with a single Java stack. 160
Andrus Adamchik @andrus.adamchik.org · 12/02/2026This sounds pretty cool. I guess JJava kernel won’t work in the browser yet (WebAssembly and all), but I am curious what it would take to make it work 000
Andrus Adamchik @andrus.adamchik.org · 22/10/2025A new milestone of JJava Jupyter kernel is out. We had a community request for a more extensible lib to build custom extensions, distros or even kernels. We did just that. Thanks to @maxandersen.xam.dk for providing feeback and PRs through the process! github.com/dflib/jjava/...github.comJJava 1.0-a6 released · dflib jjava · Discussion #101Happy to announce a new a6 milestone of DFLib JJava 1.0. JJava is a Java / JVM kernel for Jupyter. This is a pretty significant update primarily focused on the "kernel-as-platform" aspect. What we ... 040
Andrus Adamchik @andrus.adamchik.org · 13/09/2025DFLib 2, milestone 4 is out. Massive QL improvements. I finally switched all of my own projects to QL from the API-based expressions. Also some new ECharts stuff github.com/dflib/dflib/... 030
Andrus Adamchik @andrus.adamchik.org · 01/07/2025DFLib just got a parsable expression grammar. Those expressions can be thought of as parts of SQL for the purpose of column transformation, filtering and (soon) DataFrame sorting github.com/dflib/dflib/...github.comDFLib 2.0.0-M3 release · dflib dflib · Discussion #505Happy to announce M3, a major new milestone of DFLib 2.0.0. The highlight of this release is a new "expression language" : df.cols("a").merge("int(a) * 35.") // instead of // df.cols("a").merge($in... 031
Andrus Adamchik @andrus.adamchik.org · 27/06/2025Wow, just got a piece of decent code out of Gen AI - a deep clone method for an Open API descriptor tree. Still had to go line by line, adding missing properties, but the code was generally clean and meaningful. Unfortunately such success is a rare occasion 010
Andrus Adamchik @andrus.adamchik.org · 10/06/2025My first time at @lu.voxxeddays.com. Pretty exciting! In the meantime, working on getting the next DFLib milestone out of the door with the new parser of SQL-like expressions, making expressions more readable compared to the current Java DSL 000
Reposted by Andrus AdamchikMathijs Vogelzang @thijser.bsky.social · 05/06/2025Just updated my Java dataframe test & benchmark. @andrus.adamchik.org contributed an implementation for DFLib, which is now the fastest Java dataframe (not counting @duckdb.org which is much faster, but doesn't give you the dataframe syntax) github.com/mathijs81/ja... 062
Andrus Adamchik @andrus.adamchik.org · 29/05/2025The a5 version of the Jupyter kernel is officially released. Looking forward to feedback on the new Maven engine. I feel like adding a flag equivalent to "mvn -U" for snapshot refreshing may be the next logical step. github.com/dflib/jjava/... 000
Reposted by Andrus AdamchikGiulio Cesare Solaroli @gcsolaroli.mastodon.clipperz.is.ap.brid.gy · 24/05/2025Request for name suggestions: I am building a language to define data schema (similarly to what xsd and json-schema do) that is format independent, and thus it could be used to validate data serialized in multiple different formats. It’s optimized for ergonomics, as I find current schema […]mastodon.clipperz.isOriginal post on mastodon.clipperz.is 302
Andrus Adamchik @andrus.adamchik.org · 22/05/2025Been testing the soon-to-be-released DFLib JJava Jupyter kernel v1.0-a5. No more Ivy there, just pure Maven. Makes dependency management so much more reliable. 030
Reposted by Andrus AdamchikGergely Orosz @gergely.pragmaticengineer.com · 18/05/2025Every 10-20 years, a breakthrough technology promises non-developers to finally create software without needing to hire programmers. So far, every such technology resulted in the need for more devs… expert in this NEW technology (or knowing how to fix it up). Every. Time. 20468109
Andrus Adamchik @andrus.adamchik.org · 16/05/2025Enjoyed the closing keynote at @geecon.bsky.social by @jbaru.ch and Leonid Igolnik. They tried to envision an "enterprise" version of vibe coding (that's not how they worded it 🙂) Though futuristic, it came out rather convincing speaking.jbaru.ch/DVCzoZ/back-...speaking.jbaru.chBack to the Future of Software: How to Survive AI with Intent Integrity Chain by Baruch SadogurskyGreat Scott! The robots are coming for your job—and this time, they brought unit tests. Join Doc and Marty from the Software Future (Baruch and Leonid) as they race back in time to help you fight the ... 051
Reposted by Andrus AdamchikReza Rahman ☮ @reza-rahman.bsky.social · 13/05/2025Today I learned that my position at Microsoft was discontinued, amongst many others. Please reach out if it makes sense for us to explore something new together. My bio is always up-to-date. reza-rahman.me/about/ 1118
Reposted by Andrus AdamchikTriJUG @trijug.dev · 30/04/2025Tonight, @andrus.adamchik.org is giving us an overview of DFLib! 142
Andrus Adamchik @andrus.adamchik.org · 20/04/2025Server management approach is often described as "pets vs cattle". I think the same analogy might apply to data representation in apps: objects - "pets" 🐕, DataFrames - "cattle" 🐄 . Too brutal? 000
Reposted by Andrus AdamchikMax Rydahl Andersen @handle.invalid · 19/04/2025Ever been annoyed with how complex it is to execute processes in Java and handle stdin, stdout and stderr? Me too - so Introducing JBang Jash - github.com/jbangdev/jba...github.comRelease Introducing JBang Jash · jbangdev/jbang-jashJBang Jash (pronounced Jazz, the music style) is a Java library to provide way to run process or shell scripts that is fluent, predictable and with a great developer experience. To use it add a dep... 2289
Reposted by Andrus AdamchikTriJUG @trijug.dev · 13/04/2025Join us on April 30, 2025 at Deutsche Bank to see @andrus.adamchik.org give a talk on DataFrame! www.meetup.com/triangle-jav...meetup.comDataFrame - A Swiss Army Knife of Java Data Processing, Wed, Apr 30, 2025, 5:30 PM | Meetup**Note:** Slightly earlier start time than usual! Let us know how you feel about 5:30pm vs 6:00pm start times! **Abstract** When implementing an ETL job, doing data analys 052
Andrus Adamchik @andrus.adamchik.org · 09/04/2025Just published DFLib (#java DataFrame library) v1.3.0. This is a backwards-compatible maintenance release with a number of bug fixes, new statistical expressions, and an optimized vConcat operation github.com/dflib/dflib/...github.comRelease 1.3.0 · dflib/dflibDFLib 1.3.0 release Release notes #457 MissingFormatWidthException when printing Series with all empty strings #477 vConcat loses the type of the column #480 Add "NumExp.variance(..)" and "NumExp.... 031
Reposted by Andrus AdamchikMaurice Naftalin @mauricenaftalin.bsky.social · 14/03/2025#JAlba is happening again in 3 months, registration is open! It will be our 6th edition, don't miss out on attending the #Java #unconference in Edinburgh Scotland, created on the model of #JCrete. Come and meet #Java champions and experts. Register now: jalba.scotjalba.scotJAlba – JAlba – An Open Space Conference in Edinburgh 042
Andrus Adamchik @andrus.adamchik.org · 11/03/2025Just installed the newest toy - Claude Code. I like their CLI-first IDE-agnostic approach and decent “understanding” of your code base, but there are no miracles. It can can help with refactoring here and there, but it fails at “real” coding tasks. 010
Andrus Adamchik @andrus.adamchik.org · 06/03/2025When iPhones first came out there were people bragging about writing novels on an iPhone 🤷♂️ 000
Andrus Adamchik @andrus.adamchik.org · 06/03/2025“Hu said that even if product builders rely heavily on AI, one skill they would have to be good at is reading the code and finding bugs” Which will take more time than writing correct code from scratch 011
Reposted by Andrus AdamchikKate Holterhoff, PhD @kateholterhoff.com · 03/03/2025Welcome @devnexus.bsky.social crew 🍑! Celebrating w @andrus.adamchik.org @jerdog.dev at Park Bar 1151
Andrus Adamchik @andrus.adamchik.org · 28/02/2025This is where we need to improve Java DFLib charts. They show up beautifully in regular Jupyter, but GitHub notebook renderer prevents JS execution. So server-side chart creation will be needed 010
Andrus Adamchik @andrus.adamchik.org · 22/02/2025As weird as it sounds, I actually like refactoring legacy codebases. The result can be vary satisfying. But AI legacy codebases sound dreadful. Even much smaller AI-assisted PRs suck all the joy away from work. 150
Andrus Adamchik @andrus.adamchik.org · 22/02/2025The reverse Moore's law - you can keep upgrading your laptop to the latest and greatest every two years, but it still takes 10 sec to open a web browser 030
Reposted by Andrus AdamchikCay Horstmann @horstmann.com · 22/02/2025For anyone teaching Java: I posted a quick summary of new Java features that help beginners. horstmann.com/unblog/2025-... 0105
Andrus Adamchik @andrus.adamchik.org · 13/02/2025Oops, found a high-severity bug in the new BooleanSeries. It is fixed and released as 2.0.0-M2. So if you are evaluating (or already switched to) M1, please update the version to M2 000
Andrus Adamchik @andrus.adamchik.org · 12/02/2025The first milestone of DFLib 2 is out. Lots of improvements as described here: github.com/dflib/dflib/... A few examples: * 8x reduction of memory footprint of BooleanSeries * Major new capabilities in "window" expressions * Shortened aggregation syntax of "group" expressions * Heatmap charts 020
Andrus Adamchik @andrus.adamchik.org · 11/02/2025Apache Iceberg is certainly on the radar. Looking forward to attend this presentation (and luckily it doesn’t overlap with mine 🙂) 010
Andrus Adamchik @andrus.adamchik.org · 07/02/2025Just posted DFLib maintenance release 1.2.0. It has a number of bug fixes (math, resource management) and small API improvements. This is a drop-in replacement for any prior 1.*. A much bigger deal is the upcoming 2.0.0-M1 that is expected in a few days. github.com/dflib/dflib/...github.comRelease 1.2.0 · dflib/dflibDFLib 1.2.0 release. Release Notes #430 CsvLoader.nullString(String) #435 ByteSources.process() exception for single-entry source #437 ByteSource doesn't close streams in internal methods #451 Dec... 010
Andrus Adamchik @andrus.adamchik.org · 07/02/2025Glad to see that Java community is waking up to notebooks. Suddenly turns out you can do data work, visualization, experimenting, learning without switching to Python. We went a different way deciding to support Java in Jupyter. Curious to see whether DFLib Jupyter hacks are portable to JTaccuino 2102
Andrus Adamchik @andrus.adamchik.org · 06/02/2025A reminder that you can come to my DataFrames / DFLib talk @devnexus.bsky.social in March in Atlanta. Atlanta used to be home back in the day. Always enjoy coming back. And here is the code for a 40% discount on the conference ticket - SPEAK40. devnexus.com/presentation...devnexus.comDataFrame - a Swiss Army Knife of Java Data Processing 020
Andrus Adamchik @andrus.adamchik.org · 02/02/2025The more we talk about DataFrames, the better. Java needs DataFrames! 140
Reposted by Andrus AdamchikMoebius13 @moebius13.bsky.social · 02/02/2025Starting trade wars to make it easier to take over the government was literally the plot to the Star Wars prequels. 182149883018
Andrus Adamchik @andrus.adamchik.org · 02/02/2025DFLib 2.0.0-M1 is approaching. It has 40 new tasks. Now I wanted to mention just one - a great improvement in "window" transforms. Window column functions are no longer just aggregation. Now you can do "rowNum()", "cumSum()", etc. Also, just finished "Window Ops" docs at dflib.org/dflib/docs/2...dflib.orgDFLib DataFrame Documentation - v2 (alpha)Documentation for DFLib Java DataFrame library version 2. Provides a guide on how to create DataFrames from different data sources and how to use DataFrames for a variety of data transformation operat... 011
Reposted by Andrus AdamchikJay 🦋 @jay.bsky.team · 02/02/2025Good job, posters. That’s a lot of posts. 530256591583
Reposted by Andrus AdamchikTodd Ginsberg @todd.ginsberg.com · 28/01/2025TriJUG will be hosting @andrus.adamchik.org on February 18th, 2025 for his talk "DataFrame - A Swiss Army Knife of Java Data Processing". Come join us! #java #meetup #rtp www.meetup.com/triangle-jav...meetup.comLogin to Meetup | MeetupNot a Meetup member yet? Log in and find groups that host online or in person events and meet people in your local community who share your interests. 033
Reposted by Andrus AdamchikKelsey Hightower @kelseyhightower.com · 27/01/2025Now that DeepSeek is having an impact on the US stock market, I expect a huge negative press cycle designed to discredit their advancement is on the way. 1893884377
Reposted by Andrus Adamchikalice @alice.mosphere.at · 25/01/2025"god bless the european union" i repeat as i trash my remaining lightning cables 20146355
Reposted by Andrus AdamchikStephen Judkins @stephenjudkins.bsky.social · 23/01/2025love to be made a bagholder against my will 720534
Reposted by Andrus AdamchikSean Dick @seandick.net · 23/01/2025I weep for any programmer that does not revel in the deletion of code. 1195