Holden Karau
@holdenkarau.com
she/her, mostly OSS big data (Spark, Dask, Ray, and friends). I ❤️☕️🛵. I don't represent my employer. Live @ http://twitch.tv/holdenkarau , http://tech.lgbt/@holden , Twitter was @holdenkarau
Love to see small models winning, less power greener, faster, and capable of running outside of the hyperscalers :)
Great to see the team directly address transcription accuracy and latency challenges..."attaining accuracy on-par with models 6x their size while running significantly faster."
Link to the new Moonshine AI paper: arxiv.org/abs/2602.12241
Link to the new Moonshine AI paper: arxiv.org/abs/2602.12241
February 13, 2026 at 6:13 PM
Love to see small models winning, less power greener, faster, and capable of running outside of the hyperscalers :)
Reposted by Holden Karau
indeed.
"when Holden Karau created FightHealthInsurance, she really was fighting—not just for access to easy and affordable healthcare, but also for a better world for the people around her."
stackoverflow.blog/2026/02/12/h...
"when Holden Karau created FightHealthInsurance, she really was fighting—not just for access to easy and affordable healthcare, but also for a better world for the people around her."
stackoverflow.blog/2026/02/12/h...
How everyone and anyone can use AI for good - Stack Overflow
stackoverflow.blog
February 12, 2026 at 11:46 PM
indeed.
"when Holden Karau created FightHealthInsurance, she really was fighting—not just for access to easy and affordable healthcare, but also for a better world for the people around her."
stackoverflow.blog/2026/02/12/h...
"when Holden Karau created FightHealthInsurance, she really was fighting—not just for access to easy and affordable healthcare, but also for a better world for the people around her."
stackoverflow.blog/2026/02/12/h...
I’m excited to announce that I’ve joined Snowflake working OSS Apache Spark and I’ve written a post about what we’re doing careers.snowflake.com/us/en/blogar... :) (don’t worry I’m still working on Fight Health Insurance too thanks to coffee powered scaling)
Building Apache Spark™ in the Open at Snowflake
Why Holden Karau joined and what she's building at Snowflake.
careers.snowflake.com
February 12, 2026 at 2:55 PM
I’m excited to announce that I’ve joined Snowflake working OSS Apache Spark and I’ve written a post about what we’re doing careers.snowflake.com/us/en/blogar... :) (don’t worry I’m still working on Fight Health Insurance too thanks to coffee powered scaling)
Love to see @fightpaperwork.bsky.social covered in Phoebe's Stackoverflow post on AI for good: stackoverflow.blog/2026/02/11/i... :D
Is anyone using AI for good? - Stack Overflow
stackoverflow.blog
February 11, 2026 at 9:42 PM
Love to see @fightpaperwork.bsky.social covered in Phoebe's Stackoverflow post on AI for good: stackoverflow.blog/2026/02/11/i... :D
Reposted by Holden Karau
holden & fight health insurance in stack overflow blog "From that point on, I would use FightHealthInsurance as a rebuttal to the doom-and-gloom approach to AI my friends would take." 💛
stackoverflow.blog/2026/02/11/i...
stackoverflow.blog/2026/02/11/i...
Is anyone using AI for good? - Stack Overflow
stackoverflow.blog
February 11, 2026 at 8:08 PM
holden & fight health insurance in stack overflow blog "From that point on, I would use FightHealthInsurance as a rebuttal to the doom-and-gloom approach to AI my friends would take." 💛
stackoverflow.blog/2026/02/11/i...
stackoverflow.blog/2026/02/11/i...
Super stoked to be talking with Daniel Aronovich about Spark optimization ~now (10am pacific), come join us:
us06web.zoom.us/webinar/regi...
us06web.zoom.us/webinar/regi...
Welcome! You are invited to join a webinar: Apache Spark Optimization: Practical Deep Dive. After registering, you will receive a confirmation email about joining the webinar.
Join Holden Karau (Principal Engineer OSS Spark) and Daniel Aronovich (Co-Founder & CTO, DataFlint) for a practical, in-depth session on Spark optimization that goes beyond generic best practices.
We ...
us06web.zoom.us
February 11, 2026 at 6:00 PM
Super stoked to be talking with Daniel Aronovich about Spark optimization ~now (10am pacific), come join us:
us06web.zoom.us/webinar/regi...
us06web.zoom.us/webinar/regi...
Hey London friends have nothing to do on a Monday night? I’ll be giving a talk about some of the cool AI stuff you can do with Apache Spark, including appealing health insurance denials, and the infra behind it :) Come say hi! luma.com/e3bw395h
February 2, 2026 at 11:15 AM
Hey London friends have nothing to do on a Monday night? I’ll be giving a talk about some of the cool AI stuff you can do with Apache Spark, including appealing health insurance denials, and the infra behind it :) Come say hi! luma.com/e3bw395h
The KFK bar is not associated with the Kafka project, but the queue was long when I looked last night so maybe they should be….
February 1, 2026 at 10:11 AM
The KFK bar is not associated with the Kafka project, but the queue was long when I looked last night so maybe they should be….
Hanging at FOSDEM if you want to chat about Apache Spark or fighting health insurance with AI come find me :)
February 1, 2026 at 10:11 AM
Hanging at FOSDEM if you want to chat about Apache Spark or fighting health insurance with AI come find me :)
Stickers for the Icerberg meetup :) luma.com/yx3lhqu9
January 30, 2026 at 4:12 PM
Stickers for the Icerberg meetup :) luma.com/yx3lhqu9
It’s not a lot of days lately I agree with the white house but an end to pharmacy benefit manager kickbacks is long overdue.
January 16, 2026 at 2:02 AM
It’s not a lot of days lately I agree with the white house but an end to pharmacy benefit manager kickbacks is long overdue.
Need a distraction? Come and join me for hacking on @ApacheSpark today: www.youtube.com/watch?v=h1fD... / twitch.tv/holdenkarau
Spark PR Follow Up (splitting) and SPIP progress
YouTube video by Holden Karau
www.youtube.com
January 12, 2026 at 8:09 PM
Need a distraction? Come and join me for hacking on @ApacheSpark today: www.youtube.com/watch?v=h1fD... / twitch.tv/holdenkarau
Today in Holden and the magic smoke I’m surprised these light still worked…
January 9, 2026 at 2:34 AM
Today in Holden and the magic smoke I’m surprised these light still worked…
Just started reading Christina DiEdoardo’s book about Canada and Americas historic war plans for each ( amzn.to/49l14r4 ) other just as America invades another country. What a weird time to be alive. (Amazon link)
If Beaver Fights Eagle: Canada and the U.S. Prepare for War Against Each Other 1920-2025
Through two world wars, and in multiple lesser conflicts since around the world, the United States and Canada have usually fought side by side. But a small group of strategists on both sides, beginnin...
amzn.to
January 3, 2026 at 10:46 PM
Just started reading Christina DiEdoardo’s book about Canada and Americas historic war plans for each ( amzn.to/49l14r4 ) other just as America invades another country. What a weird time to be alive. (Amazon link)
Oof one of @fightpaperwork.bsky.social’s NV jetsons gave up the ghost (had this screen then got really really hot). Anyone got a lead on cheap RK1s?
December 25, 2025 at 5:12 AM
Oof one of @fightpaperwork.bsky.social’s NV jetsons gave up the ghost (had this screen then got really really hot). Anyone got a lead on cheap RK1s?
Going to do a mini stream working on Fight Health Insurance tonight (Christmas Eve) at 6pm :)
December 25, 2025 at 12:49 AM
Going to do a mini stream working on Fight Health Insurance tonight (Christmas Eve) at 6pm :)
X-mass Eve Eve Code Review Feedback Follow up on my @apachespark filter pushdown PR: www.youtube.com/watch?v=0KRt...
X-Mass Eve Eve: Filter Pushdown Land CR Feedback
YouTube video by Holden Karau
www.youtube.com
December 23, 2025 at 8:49 PM
X-mass Eve Eve Code Review Feedback Follow up on my @apachespark filter pushdown PR: www.youtube.com/watch?v=0KRt...
I'm going to hack on the "What's in in Spark 4.1 (since Spark 2.4)" chapter of High Performance Spark 2e today :) -- www.youtube.com/watch?v=xdz4...
Working on the High Performance Spark book: What's new in Spark 4.1 :D
YouTube video by Holden Karau
www.youtube.com
December 21, 2025 at 11:32 PM
I'm going to hack on the "What's in in Spark 4.1 (since Spark 2.4)" chapter of High Performance Spark 2e today :) -- www.youtube.com/watch?v=xdz4...
Come and join me for proposing a large(ish) @ApacheSpark change and see how we run the SPIP process -- www.youtube.com/watch?v=bC2y... :D
Very mini stream: Starting discussion for an SPIP around transpilation
YouTube video by Holden Karau
www.youtube.com
December 19, 2025 at 7:29 PM
Come and join me for proposing a large(ish) @ApacheSpark change and see how we run the SPIP process -- www.youtube.com/watch?v=bC2y... :D
Come and join me for a quick pre-holiday @ApacheSpark stream: www.twitch.tv/holdenkarau hacking on filter pushdown regression.
holdenkarau - Twitch
Pre-Holiday Spark PR Follow Up Stream: Updating Pushdown Logic
www.twitch.tv
December 18, 2025 at 9:51 PM
Come and join me for a quick pre-holiday @ApacheSpark stream: www.twitch.tv/holdenkarau hacking on filter pushdown regression.
I don’t know how Your Rich BFF knows when I’m on vacation but she did another great post on www.fighthealthinsurance.com today while I’m on vacation at the same hotel as last year 😝, give it a watch / share ❤️ www.instagram.com/reel/DSNbmx5...
Fight Your Health Insurance Denial -- Use AI to Generate Your Health Insurance Appeal
Fight Health Insurance is a generative AI tool to help you fight your health insurance denial. Just take a picture of your denial and it will generate an appeal for you to submit as the first part of ...
www.fighthealthinsurance.com
December 13, 2025 at 7:09 PM
I don’t know how Your Rich BFF knows when I’m on vacation but she did another great post on www.fighthealthinsurance.com today while I’m on vacation at the same hotel as last year 😝, give it a watch / share ❤️ www.instagram.com/reel/DSNbmx5...
Kicking off december with hacking on some Spark UDF acceleration adventures -- www.twitch.tv/holdenkarau :) 100% off all Holden Spark PRs today only for cyber monday :p
holdenkarau - Twitch
Apache Spark Hacking Times: Starting on UDF transpilation and random
www.twitch.tv
December 1, 2025 at 7:43 PM
Kicking off december with hacking on some Spark UDF acceleration adventures -- www.twitch.tv/holdenkarau :) 100% off all Holden Spark PRs today only for cyber monday :p
Reposted by Holden Karau
@julianwood.com talks with @holdenkarau.com about turning a decade of Apache Spark expertise into an AI tool that fights insurance denials. fighthealthinsurance.com is live and free. The business model? Step one ✅ Step two ❓ Step three: profit 🤷
From Apache Spark to Fighting Health Insurance Denials • Holden Karau & Julian Wood • GOTO 2025
This interview was recorded for GOTO Unscripted. #GOTOcon #GOTOunscripted
https://gotopia.tech
Check out more here:
https://gotopia.tech/articles/410
Holden Karau - Co-Founder at Fight Health…
youtu.be
November 17, 2025 at 1:00 PM
@julianwood.com talks with @holdenkarau.com about turning a decade of Apache Spark expertise into an AI tool that fights insurance denials. fighthealthinsurance.com is live and free. The business model? Step one ✅ Step two ❓ Step three: profit 🤷
Come and join me for more hacking on @apachespark today -- www.youtube.com/watch?v=u5F_... I'm going to be working on github.com/apache/spark...
Spark PR adventures: Determinism Issues (maybe?)
YouTube video by Holden Karau
www.youtube.com
November 13, 2025 at 6:59 PM
Come and join me for more hacking on @apachespark today -- www.youtube.com/watch?v=u5F_... I'm going to be working on github.com/apache/spark...
Reposted by Holden Karau
The benevolent dictator model feels tempting for #OSS - faster, fewer debates. Then a PR argument with the single person in charge reminds me:
Speed isn’t health. Community is.
Speed isn’t health. Community is.
November 7, 2025 at 7:48 PM
The benevolent dictator model feels tempting for #OSS - faster, fewer debates. Then a PR argument with the single person in charge reminds me:
Speed isn’t health. Community is.
Speed isn’t health. Community is.