Gunnar Morling
@gunnarmorling.dev
Technologist @ Confluent · Ex-lead of Debezium · Spec lead of Bean Validation 2.0 · Creator of Hardwood, kcctl, JfrUnit, MapStruct · Java Champion · morling.dev · 🚴
📝 "A Fast Path for Fixed-Length Lists in Parquet" New blog dropped, discussing how we optimize reading effectively fixed-length lists (think vector embeddings) in Hardwood. Up to 3.9× faster, getting to the level of flat columns for larger lists. 👉 www.morling.dev/blog/fast-pa...
Spent the weekend on a fun one: you can now inspect Parquet files in your browser via #Hardwood, and the file never leaves your machine 🤓. Yes, that's right, the hardwood dive TUI compiled ahead-of-time to #WebAssembly, via GraalVM's Web Image. Try it yourself at hardwood.dev/experiments/...!
📝 "Improved Column Reader API, First Cut of Geospatial Support: Hardwood 1.0.0.CR1 Is Available" Next stop (hopefully 😇): Hardwood 1.0 Final! 👉 www.morling.dev/blog/improve...
1 Billion Row Challenge creator @gunnarmorling.dev is back with #Hardwood - a zero-dependency, ultra-fast #Java parser for #ApacheParquet. 🎧 Listen to the #InfoQ #podcast to learn more about Hardwood’s architecture, parallelization & performance optimization ⇨ bit.ly/4wP8jlR #AI
Chasing Efficient Java Development: From 1BRC to Developing Hardwood AI Natively
Gunnar Morling, technologist at Confluent and Java Champion, shares his experiences with building high-performance applications in Java, especially in the data space. He shares insights from experimen...
bit.ly
The slides from my #Current London talks are up 🥳. - "Transactional Change Stream Processing With Debezium and Apache Flink" speakerdeck.com/gunnarmorlin... - "Hardwood: Building a Parquet Parser From Scratch (With a Little Help From AI)" speakerdeck.com/gunnarmorlin...
Now attending the World Premiere conference talk on Hardwood: the new Apache Parquet parser by @gunnarmorling.dev at #Current26
Woot, woot: 2^8 🌟s for the #Hardwood GitHub repo 🥳! Might be a small step, but so great to see the interest in the project. #ApacheParquet github.com/hardwood-hq/...
I don’t buy the idea that libraries will go away since everyone can just write their own now. Maybe for small internal company use-cases. But libraries are not just code, they’re time invested in edge cases, they’re hundreds of hours of human eyes. I don’t want to replace that.
📝 Blogged: "VARIANT Support, Interactive Parquet File TUI: Hardwood 1.0.0.Beta2 Is Out" The new version of the #Hardwood parser for Apache Parquet comes with support for VARIANT columns, a text-based UI for analysing Parquet files, better performance, and more. 👉 www.morling.dev/blog/variant...
📝 "Hardwood Reaches Beta: S3, Predicate Push-Down, CLI, and More" Happy to announce Hardwood 1.0.0.Beta1, adding S3 support, predicate push-down for both local and remote files, Avro bindings, a CLI for inspecting Parquet files, a new website, and much more. 👉 www.morling.dev/blog/hardwoo...
And just like that, it's time for March's Interesting Links in the Data and AI World! 👉🏻 rmoff.net/2026/03/25/i... With links from great folk including @gunnarmorling.dev, @tomcooper.dev, @sqlliz.bsky.social, @tanelpoder.com, @eatonphil.bsky.social, @larahogan.bsky.social, @almog.xyz, and more!
Interesting links - March 2026
rmoff.net
🥳 Just merged support to #Hardwood for reading Parquet files directly from S3! Including projections and predicate push-down (row group level), to fetch only the actually required column chunks, thus limiting the amount of data downloaded from the object store. Should be ready to ship next week!
Inspired by @gunnarmorling.dev, I've added a page to my blog about how I do, and don't, use AI on my blog. tl;dr: NEVER for writing content. gross. But, for plenty else! 👉🏻 rmoff.net/ai/
How I do, and don’t, use AI on this blog
rmoff.net
If you want to learn more about the Variant type in Parquet, Aihua Xu and @andrewlamb1111.bsky.social wrote a great blog post on the project blog. parquet.apache.org/blog/2026/02...
Variant Type in Apache Parquet for Semi-Structured Data
Introducing Native Variant Type in Apache Parquet
parquet.apache.org
✍🏻 Interesting Links in the Data & AI World, February 2026 Links from @gunnarmorling.dev, @nbuesing.bsky.social, @ssp.sh, @sap1ens.com, @neelesh.bsky.social, @rstephens.me, @justincormack.bsky.social, @sogrady.org, @simonwillison.net, @cassidoo.co, and more! 🔗 rmoff.net/2026/02/27/i...
Interesting links - February 2026
rmoff.net
"Are we using AI for building Hardwood? Absolutely. Is Hardwood vibe-coded? Absolutely not." Coding agents are incredibly powerful, but they're no magic wand. Sharing some experiences with using AI for building a relatively low-level code base like a Parquet parser in the #Hardwood announcement 👇.
Gunnar Morling@gunnarmorling.dev · 5mo ago📝 "Hardwood: A New Parser for Apache Parquet" Today is the day--beyond excited to share the first release of #Hardwood, a new parser for the Apache #Parquet file format, optimized for minimal dependencies and great performance. 👉 www.morling.dev/blog/hardwoo...
Interesting usage of the lessons learned during the #1BRC contest !
Gunnar Morling@gunnarmorling.dev · 5mo ago📝 "Hardwood: A New Parser for Apache Parquet" Today is the day--beyond excited to share the first release of #Hardwood, a new parser for the Apache #Parquet file format, optimized for minimal dependencies and great performance. 👉 www.morling.dev/blog/hardwoo...
📝 "Hardwood: A New Parser for Apache Parquet" Today is the day--beyond excited to share the first release of #Hardwood, a new parser for the Apache #Parquet file format, optimized for minimal dependencies and great performance. 👉 www.morling.dev/blog/hardwoo...
Woot, woot, tackled my personal final boss, the Maven release plug-in, and we now have a fully automated release pipeline for hashtag#Hardwood. Gonna do some more testing, but we should be really close now to a first tagged release on Maven Central 🥳. Thx to @andresalmiray.com for all the help!
Most folks think of #Debezium as source connectors only, but it also provides a JDBC sink for end-to-end data pipelines. Great post by the team at Zepto on their contributions, including an upsert reduction buffer to cut load on the sink database. OSS FTW 🚀! 👉 blog.zeptonow.com/debezium-at-...
@gunnarmorling.dev has written a great post about conference talks (I wish I'd written it myself): www.morling.dev/blog/ten-tip...
Ten Tips to Make Conference Talks Suck Less
Table of Contents 1. 💦 Rehearse, Rehearse, Rehearse 2. 🎬 Start With a Mission 3. 📖 Tell a Story 4. 👀 Look at the Audience, Not Your Slides 5. 🧹 Put Less Text on Your Slides. Much Less 6. ✂️ Tailor the...
morling.dev
Today is a great day to verify you don't get yourself locked out of any 2FA-secured accounts when losing your phone. Print out back-up codes, set up fallback keys, etc. It takes just a few moments and can save you massive headaches later on.
It never stops being funny how Claude Code is patting its own should for the amazing job it's doing 🤣.
Discover how #DataFrames are transforming #DataOrientedProgramming in #Java! Analyze the #1BRC challenge & see how Java frameworks can outperform Python in memory management without sacrificing readability. Discover how DataFrames elevate your Java programming experience ⇨ bit.ly/4avEDzZ
Are You Missing a Data Frame? The Power of Data Frames in Java
Vladimir Zakharov explains how DataFrames serve as a vital tool for data-oriented programming in the Java ecosystem. By analyzing The One Billion Row Challenge, he shares how Java frameworks can outpe...
bit.ly
Spent some time to make the #Hardwood parser for Parquet files a little faster; The engine parallelizes better now, a full parse of 720 MB of the NYC taxi ride data set--summing up the values from three columns--takes about 2.3 sec on my laptop. 👉 github.com/hardwood-hq/...
We’re doing an Agentic Coding conference in Hamburg on March 22nd! 🎉 Not many details yet, but super early bird tickets are on sale and selling fast. Super excited about this one! #hamburg luma.com/45lfeyeh
Agentic Conf Hamburg 2026 · Luma
From meetup to conference. After four sold-out meetups and ~ 1000 members, it's time for the next step: The first agentic.hamburg conference on March 22, 2026.…
luma.com
