top | item 46540498

The Jeff Dean Facts

558 points| ravenical | 1 month ago |github.com

184 comments

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kentonv|1 month ago

Hey! I created Jeff Dean Facts! Not the jokes themselves, but the site that collected them.

It was in 2008 I think (give or take a year, can't remember). I worked at Google at the time. Chunk Norris Facts was a popular Internet meme (which I think later faded when he came out as MAGA, but I digress...). A colleague (who wishes to remain anonymous) thought the idea of Jeff Dean Facts would be funny, and April 1st was coming up.

At the time, there was a team working on an experimental web app hosting platform code named Prometheus -- it was later released as App Engine. Using an early, internal build I put together a web site where people could submit "facts" about Jeff Dean, rate each other's facts on a five-star scale, and see the top-rated facts. Everything was anonymous. I had a few coworkers who are funnier than me populate some initial facts.

I found a few bugs in Prometheus in the process, which the team rapidly fixed to meet my "launch date" of April 1st. :)

On the day, which I think was a Sunday, early in the morning, I sent an email to the company-wide "misc" mailing list (or maybe it was eng-misc?) from a fake email address (a google group alias with private membership), and got the mailing list moderator to approve it.

It only took Jeff an hour or two to hack his way through the back-end servers (using various internal-facing status pages, Borg logs, etc.) to figure out my identity.

But everyone enjoyed it!

My only regret is that I targeted the site specifically at Jeff and not Sanjay Ghemawat. Back then, Jeff & Sanjay did everything together, and were responsible for inventing a huge number of core technologies at Google (I have no idea to what extent they still work together today). The site was a joke, but I think it had the side effect of elevating Jeff above Sanjay, which is not what I intended. Really the only reason I targeted Jeff is because he's a bit easier to make fun of personality-wise, and because "Jeff Dean Facts" sort of rolls off the tongue easier that "Sanjay Ghemawat Facts" -- but in retrospect this feels a little racist. :(

My personal favorite joke is: Jeff Dean puts his pants on one leg at a time, but if he had more than two legs, you'd see his approach is actually O(log n).

sghemawat|1 month ago

Hi Kenton! No worries at all. I tend to be quieter than Jeff anyway (less public speaking etc.) and I am happy to not have a dedicated website. :-). -Sanjay

ariwilson|1 month ago

Hi Kenton! I was the recent grad you handed this web app off to after you built it, so I expanded Jeff Dean Facts so that anyone could create and rate facts about anyone at Google :). There were a ton of team in-jokes added before I stopped working on it - O(5k) IIRC! :)

This web app was also how I learned the pain of maintaining a live web service with a lot of ever-changing dependencies. How I sighed when the AppEngine version changed and I had to fix things again...

I handed it off again before I left Google but I have no memory of who that was to unfortunately :(.

peddling-brink|1 month ago

I’m no expert, but I certainly wouldn’t call that racism. Bias, absolutely. And it’s important that we acknowledge our biases.

But in a more literal sense, the chance of your joke landing was likely higher due to the things that you stated and due to your audience and their biases.

I don’t see your joke as being in any way harmful towards Sanjay aside from potential knock on effects of Jeff Dean being more popular. But if you try to calculate every second and third order consequence of everything that you do, let alone any moments of humor you might have.. Well, you might as well lock yourself in a cell now.

vessenes|1 month ago

Re Jeff and Sanjay - they recently were on Dwarkesh together I believe - so it looks like the partnership is still going strong. Regarding Dean over Ghemawat facts, the vibe from the convo is that Sanjay is the (very slightly) junior partner of the two, or at least he lets Jeff do more of the talking. Very, very nice vibes hearing them talk, and their war stories are clearly nuts.

oncallthrow|1 month ago

> but in retrospect this feels a little racist. :(

It’s not racist. It’s just to do with name length.

iambateman|1 month ago

Ah but it’s not racist. It can’t be. Jeff and Sanjay have never had race conditions.

:)

omoikane|1 month ago

> My only regret is that I targeted the site specifically at Jeff and not Sanjay Ghemawat.

Later version of the site was generalized so that people can submit facts for any user. I think Jeff Dean still has all the funniest fact though.

swyx|1 month ago

> Jeff & Sanjay did everything together,

my nonexpert impression is jeff keeps much more of a public profile. hence the natural celebrity goes to him. was this not true way back in the day?

scrame|1 month ago

My further comment will be buried, but its a rip on Chuck Norris facts, and was pretty ... whatever ... "geek culture". That was only proved by Chuck Norris' endorsement of Mike Huckabee back in 2007: https://www.youtube.com/watch?v=--EGyU57efY

liquidgecka|1 month ago

That meme started in early 2007 I believe. I started in 2006 and was in ZRH by 2008 and it was around long before I made that move.

westurner|1 month ago

Maybe both in the URL?

You could add a meme generator that's like the Django docs tutorial with the internet web-poll

ctxc|1 month ago

"Why do you pick on Protocol Buffers so much?

Because it’s easy to pick on myself. :)"

Damn!

bummy_commenter|1 month ago

What makes it feel a little racist?

scottlamb|1 month ago

> When Jeff Dean goes on vacation, production services across Google mysteriously stop working within a few days. This is actually true. ... It's not clear whether this fact is really true, or whether this line is simply part of the joke, so I've omitted the usual (TRUE) identifier here. Interpret this as you see fit :)

I think this one's true-ish. Back in the day when Google didn't have good cron services for the corp and production domains [1], Jeff Dean's workstation ran a job that made something called (iirc) the "protocol buffer debug database". Basically, a big file (probably an sstable) with compiled .proto introspection data for a huge number of checked-in protobufs. You could use it to produce human-readable debug output from what was otherwise a fairly indecipherable blob. I don't think it was ever intended for production use, but some things that shouldn't have ended up using it. I think after Jeff had been on vacation for a while, his `prodaccess` credentials expired, the job stopped working, maybe the output became unavailable, and some things broke.

Here's a related story I know is true: when I was running Google Reader, I got paged frequently for Bigtable replication delay, and I eventually traced it to trouble accessing files that shared GFS chunkservers with this database. I mentioned it on some mailing list, and almost immediately afterward Jeff Dean CCed me on a code review changing the file's replication from r=3 to r=12. The problem went away.

[1] this lasted longer than you would expect

chubot|1 month ago

Ha, I also recall this fact about the protobuf DB after all these years

Another Jeff Dean fact should be "Russ Cox was Jeff Dean's intern"

This was either 2006 or 2007, whenever Russ started. I remember when Jeff and Sanjay wrote "gsearch", a distributed grep over google3 that ran on 40-80 machines [1].

There was a series of talks called "Nooglers and the PDB" I think, and I remember Jeff explained gsearch to maybe 20-40 of us in a small conference room in building 43.

It was a tiny and elegant piece of code -- something like ~2000 total lines of C++, with "indexer" (I think it just catted all the files, which were later mapped into memory), replicated server, client, and Borg config.

The auth for the indexer lived in Jeff's home dir, perhaps similar to the protobuf DB.

That was some of the first "real Google C++ distributed system" code I read, and it was eye opening.

---

After that talk, I submitted a small CL to that directory (which I think Sanjay balked at slightly, but Jeff accepted). And then I put a Perforce watch on it to see what other changes were being submitted.

I think the code was dormant for awhile, but later I saw someone named Russ Cox started submitting a ton of changes to it. That became the public Google Code Search product [2]. My memory is that Russ wrote something like 30K lines of google3 C++ in a single summer, and then went on to write RE2 (which I later used in Bigtable, etc.)

Much of that work is described here: https://swtch.com/~rsc/regexp/

I remember someone telling him on a mailing list something like "you can't just write your own regex engine; there are too many corner cases in PCRE"

And many people know that Russ Cox went on to be one of the main contributors to the Go language. After the Code Search internship, he worked on Go, which was open sourced in 2009.

---

[1] Actually I wonder if today if this could perform well enough a single machine with 64 or 128 cores. Back then I think the prod machines were something like 2, 4, or 8 cores.

[2] This was the trigram regex search over open source code on the web. Later, there was also the structured search with compiler front ends, led by Steve Yegge.

kentonv|1 month ago

I submitted this "fact" and it is indeed a true story, exactly as you said.

The "global protobuf db" had comments all over it saying it's not intended for production-critical tasks, and it had a lot of caveats and gotchas even aside from being built by Jeff's desktop, but it was so convenient that people naturally ended up using it anyway.

btilly|1 month ago

In 2010, due to the China hacking thing, Google locked down its network a lot.

At least one production service went down because it relied on a job running on Jeff Dean's personal computer that no longer had access. Unfortunately I forget what job it was.

jeffbee|1 month ago

The other thing that ran under Jeff's desk for a long time was Code Search, the old one.

andy99|1 month ago

My highlight are

  During his own Google interview, Jeff Dean was asked the implications if P=NP were true. He said "P = 0 or N = 1." Then, before the interviewer had even finished laughing, Jeff examined Google's public certificate and wrote the private key on the whiteboard.

  Jeff Dean wrote an O(n^2) algorithm once. It was for the Traveling Salesman Problem
I read it more as a parody of The Most Interesting Man in the World as opposed to Chuck Norris.

jakevoytko|1 month ago

"Chuck Norris facts" was a text-only meme format from the mid '00s. Stuff like "Chuck Norris is the only man to ever defeat a brick wall in a game of tennis" or "When Chuck Norris does push-ups, he doesn't push himself up, he pushes the Earth down." The Jeff Dean Facts use the same format. It doesn't have anything to do with Chuck Norris himself.

mcmcmc|1 month ago

The Dos Equis ad campaign came well after Chuck Norris jokes

dust-jacket|1 month ago

OK "Jeff Dean once shifted a bit so hard it ended up on another computer" got a proper chuckle from me

chihuahua|1 month ago

This is the basis for the software that allows you to use a single mouse to control a mouse pointer on several computers.

hvenev|1 month ago

> Jeff once simultaneously reduced all binary sizes by 3% and raised the severity of a previously known low-priority Python bug to critical-priority in a single change that contained no Python code.

This sounds really plausible. A change to the C toolchain/library (for example, specialized/inlined memcpy) may affect binary sizes significantly, and may change the behavior of something the C standard leaves undefined (for example, memcpy with overlapping arguments).

astrange|1 month ago

I have such a Python bug right now because of something that fork()s in a way that can't posix_spawn(). One of those is a lot easier to make performant than the other.

thevillagechief|1 month ago

> When Jeff gives a seminar at Stanford, it's so crowded Don Knuth has to sit on the floor. (TRUE)

That's actually funny and cool if true. I think what's even more impressive is that this stuff was all pre-AI boom.

dekhn|1 month ago

Yes, Jeff told me this one personally. Knuth came in right before the talk started and the room was full. I think somebody later gave up a seat for him.

scottlamb|1 month ago

It probably is. I think the same thing happened when Randall Munroe (of xkcd fame) gave a talk at Google. I was there, it was crowded, and Don Knuth showed up. 90% sure he sat on the floor.

ChrisMarshallNY|1 month ago

Love it!

> Jeff Dean compiles and runs his code before submitting, but only to check for compiler and CPU bugs.

Sadly, I have encountered this, in many "Non-Jeff-Dean" developers.

Xenoamorphous|1 month ago

What I’ve found is some really average developers thinking they’re Jeff Dean, or at least have that attitude.

postscapes1|1 month ago

I am only semi technical so most of these go right over my head, but after watching a ton of Jeff Dean interviews, etc it is really fun to see how a 10-100x engineer can operate over such a long career (while seemingly a normal and kind person to boot)

m1ck|1 month ago

My 3 When Graham Bell invented the telephone, he saw a missed call from Jeff Dean. Jeff Dean's PIN is the last 4 digits of pi. As a young boy, Jeff Dean reprogrammed his Etch A Sketch to play Tetris.

tanseydavid|1 month ago

I have been laughing about the PIN/pi joke over and over for the past 24 hours.

bhickey|1 month ago

I once mailed a CL to Sanjay. He replied, "This is outside of my expertise. Can you send it to Jeff?"

seanmcdirmid|1 month ago

One of my more junior teammates got their CL assigned to Sanjay for review, she had no idea who he was and I just told her to look at all her new badges tomorrow.

stogot|1 month ago

I didn’t think I’d laugh, but a few of these cheered me up. Laughter is such a good medicine.

callumprentice|1 month ago

Agreed! I felt the same way but sitting here with my morning coffee chuckling away. A good start to the day.

delichon|1 month ago

Ok I'll try. Jeff Dean read the instructions on his family sized bottle of shampoo in the shower. They said lather, rince, repeat. He almost died of hypothermia, but wrote a goto in conditioner just in time.

justinchen7|1 month ago

Funny, but also a reminder of how rare it is to find people who combine deep technical ability with the calm, high-leverage decision-making that scales teams. Memes aside, those are the folks who quietly shape entire fields.

ripe|1 month ago

What does "readability" mean? It's mentioned in several of these jokes: "binary readability", etc.

bubblicious|1 month ago

readability grants a code reviewer the power to approve changes in a specific language

utopcell|1 month ago

It is a formal process via which it is confirmed that you know enough of X to submit code to the codebase, where X can be c++, java, python, etc. If you don't have X readability, then, in addition to your main code reviewer, you need to have a readability reviewer look at your code, who will be focusing only on X, not the logic of your code.

leopoldj|1 month ago

A few more:

Jeff Dean doesn't use a compiler; he just glares at his source code until it executes.

Jeff Dean once optimized a sleep(10) call to return in 5 seconds.

Jeff Dean’s keyboard doesn’t have a Backspace key; he simply doesn't make mistakes.

/end. There's no need to get up. I will see myself out.

VikingCoder|1 month ago

In an alternate universe, pi is rational, and Jeff Dean is not.

Bost|1 month ago

The TheJeffDeanFacts repo contains no issues. (TRUE)

nickstaggs|1 month ago

Maybe I just run in different circles but I was always under the impression that the so called Chuck Norris of programming was Jon Skeet, another rather "famous" google employee

freeCandy|1 month ago

To me, the Chuck Norris of programming has to be Fabrice Bellard

billbrown|1 month ago

He's the Chuck Norris of StackOverflow, maybe.

dysoco|1 month ago

Yeah I thought exactly the same, but I guess Jon Skeet is from a different era altogether, we're moving into a world where many programmers perhaps have never even entered StackOverflow. I feel old.

shadowgovt|1 month ago

I remember one that isn't in the list. Paraphrasing:

"Jeff Dean has access to the priority above P1. He's only used it once. It's why February only has 28 days."

yongjik|1 month ago

I also remember that but I think it was attributed to someone else. The site hosted several (internally famous person) facts, but none of them were as famous as Jeff Dean.

furyofantares|1 month ago

> Unsatisfied with constant time, Jeff Dean created the world's first O(1/n) algorithm.

I can think of a lot of 1/n algorithms! Head, Tail...

nojvek|1 month ago

Those are still O(1)

bananapub|1 month ago

Someone should IARC the internal one.

squigz|1 month ago

"When God said: "Let there be light!", Jeff Dean was there to do the code review."

dekhn|1 month ago

I think this makes more sense: "When God said: "Let there be light!", Jeff Dean said "LGTM, Approve"

sidcool|1 month ago

Jeff Dean achieved a Weismann score of 42.

desi_ninja|1 month ago

We need a Dave Cutler facts equivalent too. But the ppl who could have made this are probably retired or

keybored|1 month ago

Guy happens to be the lead of Google AI right now.

lysace|1 month ago

My outsider understanding: Google AI (a Google team which Jeff Dean ran) was merged with DeepMind to create Google DeepMind (a subsidiary of Alphabet, like Google).

Demis Hassabis is the CEO of Google DeepMind and Jeff Dean is now the Chief Scientist of Google.

https://en.wikipedia.org/wiki/Google_DeepMind

https://research.google/people/jeff/

I joined Google in mid-1999, and I'm currently Google's Chief Scientist, focusing on AI advances for Google DeepMind and Google Research. My areas of focus include machine learning and AI and applications of AI to problems that help billions of people in societally beneficial ways. I have a broad variety of interests, including machine learning, large-scale distributed systems, computer systems performance, compression techniques, information retrieval, application of machine learning to search and other related problems, microprocessor architecture, compiler optimizations, and the development of new products that organize information in new and interesting ways.

saagarjha|1 month ago

What’s Mustang? Web search?

mike_hearn|1 month ago

It is or was the serving component of the main index. The part that does the posting list intersections and lookups.

utopcell|1 month ago

Web Search Serving. Many generations ago.

scrame|1 month ago

I get jeff dean is a great engineer and probably had nothing to do with this, but I always thought this "googly" memeing of chuck norris was so lame.

I mean, chuck norris even did it to endorse mike huckabee. https://www.youtube.com/watch?v=--EGyU57efY

eatbitseveryday|1 month ago

I’m not sure I’m comfortable idolizing someone living like this

rednafi|1 month ago

Another one I have heard is "Jeff Dean's stare can fix bitrot"

esafak|1 month ago

It's nice that a company has senior engineers that are known by name and looked up to. It shows that engineers are valued, and a meritocracy exists.

dekhn|1 month ago

Yes, but the downside is even highly accomplished engineers feel unworthy. For example, when I started in 2008, they said everybody should make a "Google Resume" (ongoing list of all the stuff you did at Google) and linked to Jeff's as an example.

He rewrote the entire indexing pipeline at a critical time enabling Google's rapid growth... created mapreduce... helped create bigtable & gfs... wrote the search engine that ran for over a decade... numerous improvements to search and ads quality (back in the days when search and ads quality meant something)... and that was just the first few years.

advisedwang|1 month ago

> It shows that engineers are valued

yep

> and a meritocracy exists

not necessarily. It shows the system got one excellent engineer to an appropriate position. But it doesn't show that the system isn't promoting bozos too, and keeping other excellent engineers down.

m00dy|1 month ago

can he beat llms ? don't think so.

dekhn|1 month ago

Jeff is so good at AI, he invented much of the infrastructure to implement LLMs, mostly to increase the productivity of other programmers.

bigstrat2003|1 month ago

Anyone of modest competence can beat LLMs.

lookingdesk|1 month ago

Jeff Dean liquidated Google's entire AI ethics team because they wouldn't revise an academic publication to align with the corporate PR spin on AI.

chubot|1 month ago

This is overstating it by a lot. Jeff was the AI lead at the time, and there was a big conflict between management and the ethics team

And I actually think Google needs to pay more attention to AI ethics ... but it's a publically traded company and the incentives are all wrong -- i.e. it's going to do whatever it needs to do keep up with the competition, similar to what happened with Google+ (perceived competition from Facebook)

tziki|1 month ago

You mean he fired one person who threatened to quit if the changes to the paper weren't to their liking? Or am I misremembering?

whynotminot|1 month ago

As far as I can tell, no one seems to think much of value was lost.

lemoncucumber|1 month ago

That incident was the first time I ever heard of Jeff Dean and remains the main thing I associate him with.

morcus|1 month ago

I'm having trouble following what exactly this means.

So Jeff wanted the team to modify an existing publication to fit the PR spin on AI, the ethics team refused, and Jeff dissolved the team?

shemnon42|1 month ago

Just another Jeff Dean optimizing out unneeded code story.

jackblemming|1 month ago

Jeff Dean is a lot smarter than me, more accomplished, and more talented. But let’s be honest. He was a big part of TensorFlow and TensorFlow sucks. And I imagine it reflects a lot about Jeff Dean internally. Smart, clever, but maybe over complicated or over engineered. And that itself reflects hugely at what Google tends to like, and why he’s so successful (at Google).

And if we’re being brutally honest, I wonder how he would have faired at somewhere like Bell Labs ;)

utopcell|1 month ago

Let's be honest: you don't have the slightest idea about what you're talking about.