Joe Hellerstein
Joe Hellerstein
@joehellerstein.bsky.social
Computer things @Berkeley and music things elsewhere.
Reposted by Joe Hellerstein
Let’s collaborate on democratizing insights from tabular data in Amsterdam! ✨

PhD directions: 1) fundamental techniques for tabular foundation models, 2) reliable mechanisms for AI-powered tabular data analysis.

Sharing w/ friends appreciated! ⬇️
ellis.eu ELLIS @ellis.eu · Jun 5
🏹 Job alert: 2 fully-funded PhD Positions at Table Representation Learning Lab - @ellisamsterdam.bsky.social

📍 Amsterdam 🇳🇱
📅 Apply by June 30
🔗 More info: https://bit.ly/4519pj1
Open positions | TRL Lab
bit.ly
June 5, 2025 at 3:36 PM
The last blog post in my miniseries on CRDTs is up!

jhellerstein.github.io/blog/crdt-in...

Mix of pragmatism and formalism.

There's actually a small result in there that may be novel: Strong Eventual Consistency !=> Determinism. Curious to hear whether they've seen this result elsewhere.
CRDTs #4: Convergence, Determinism, Lower Bounds and Inflation
The CRDT literature sometimes leaves room for mathematical ambiguity. Maybe because the bulk of the work tends to be targeted at systems researchers and…
jhellerstein.github.io
June 5, 2025 at 1:42 AM
Next blog post in the CRDT Series is up!

This one is for the developers... stay safe out there, folks.

jhellerstein.github.io/blog/crdt-do...
CRDTs #3: Do Not Read!
Ever used a CRDT, thought you were safe, and—boom—you bought a Ferrari you didn't mean to? It could happen to you! The truth is that CRDTs are dangerous to…
jhellerstein.github.io
May 28, 2025 at 8:37 PM
Good thread. Thoughtful as always.
I have not paid a ton of attention to the uproar over RTO policies, bc we are all in on distributed teams and not going back.

My impression (via social media) has been that these were shadow layoffs.

Last month I asked an investor why they are doing RTO. He said: "Retention, mostly. And morale."
May 28, 2025 at 4:28 AM
(Catching up to my LI feed).

Next blog post is out! This is the first real post in a short series on CRDTs, an idea that has some currency in the distributed programming community, but one that comes with a number of sharp edges. Be careful out there!

jhellerstein.github.io/blog/crdt-tu...
CRDTs #1: Turtles All the Way Down
This is the 1st post in a series of 4 detailed posts I'm doing on CRDTs. Please see the intro post for context. Modern distributed systems often seem to rest on…
jhellerstein.github.io
May 22, 2025 at 11:06 PM
Blog relaunch! Bbye wordpress, hello github.

If you're into SW dev, cloud, databases, distributed systems, automatic codegen ... or data and CS in general... check it out.

As a warmup, I'm starting with a series of posts on CRDTs. Intro post up now: jhellerstein.github.io/blog/crdt-in...
A Run of CRDT Posts
Over the next few days, I'm going to post a number of observations about CRDTs: Convergent Replicated Data Types. These are data structures that aspire to help…
jhellerstein.github.io
May 22, 2025 at 11:05 PM
Wow! @arvind.bsky.social giving an awesome keynote including discussion of VegaExpress and GoFish interactive vis libraries from his group. #EPICRetreat #UCBerkeley.
April 16, 2025 at 9:01 PM
Here’s a provocative example from JD Zamfirescu-Pereira on ways that humans and LLMs can get misaligned on expectations. Is the LLM lying? Is it just emitting tokens? How do people interpret this? #EPICRetreat #UCBerkeley.
April 16, 2025 at 5:27 PM
Reposted by Joe Hellerstein
The SF Systems Meetup is back! On 2/27, we're excited to have headline talks from the creator of FizzBee and a research collaborator with Signal. This is going to be a super fun night diving deep into making distributed protocols work, hope you'll join us! lu.ma/vqjf30k3
SF Systems Meetup: Correctness and Security for Distributed Systems · Luma
The SF Systems Meetup is back for the new year! This meetup, our theme is correctness and security. It's easy to write a distributed protocol, but very hard to…
lu.ma
February 13, 2025 at 8:47 PM
In some kind of sad watershed, today was the day as a professor when I live-ChatGPT'ed the answer to a question in a Zoom with my PhD student and his undergrad mentees.

But hey, let's paint it in a positive light: this was a demonstration of using the right tool at the right time.
February 13, 2025 at 7:15 PM
Reposted by Joe Hellerstein
Operationalizing Machine Learning: An Interview Study by @joehellerstein.bsky.social, @adityagp.bsky.social, et al. Particularly love the part on "Retrofitting Explanations".
#MachineLearning #MLOps #Datascience.
arxiv.org/pdf/2209.09125
February 6, 2025 at 7:39 PM
Sunset in #Berkeley these days is a perfect field goal over the golden gate bridge. Shifts quite a ways north during the summer.
January 23, 2025 at 6:50 PM
2025. What a time to be alive!
January 8, 2025 at 5:42 PM
Reposted by Joe Hellerstein
It’s incredibly beautiful that President Carter is our emissary on a Voyager probe. His words live on across our galaxy!
December 30, 2024 at 4:25 AM
Reposted by Joe Hellerstein
Thrilled to share that our paper “Flo: A Semantic Foundation for Progressive Stream Processing” (with @mpmilano.bsky.social, Alvin Cheung, and @joehellerstein.bsky.social) will appear at POPL 2025! Check out the preprint at arxiv.org/abs/2411.08274, and read on for more!
Flo: a Semantic Foundation for Progressive Stream Processing
Streaming systems are present throughout modern applications, processing continuous data in real-time. Existing streaming languages have a variety of semantic models and guarantees that are often inco...
arxiv.org
December 3, 2024 at 8:26 PM
Sunset over SF looked promising again today so we went down to the bay to take it in.
December 3, 2024 at 6:20 AM
Sunset over SF was stellar today.
December 2, 2024 at 4:01 AM
Reposted by Joe Hellerstein
Just when I thought I've seen it all, a PostgreSQL extension shows up that allows you to embed a SQLite database inside a table. github.com/frectonz/pgl...
November 19, 2024 at 2:19 PM
The legendary Phil Bernstein talking @BerkeleySky about his work in sw libraries for DPUs. Phil was paving the way for relational DBs and transactions in the 70s, and is still doing deep, detailed technical work. @Berkeley_EECS @BerkeleyDataSci
November 1, 2024 at 7:44 PM
HT Remy Wang, UCLA.
September 28, 2023 at 5:43 PM
Berkeley Data Systems and Foundations (DSF) in the house! With special guests from the awesome Simons Institute semester of database theory (HT NEU db group).
September 28, 2023 at 1:47 AM