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The Jeff Dean Facts

550 points by ravenical

by kentonv

16 subcomments

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).

by scottlamb

4 subcomments

> 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

by andy99

2 subcomments

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.

by pss314

0 subcomment

New Yorker published an interesting article on Jeff Dean and Sanjay Ghemawat few years ago - The Friendship That Made Google Huge [0]
[0]: https://www.newyorker.com/magazine/2018/12/10/the-friendship...

by dust-jacket

1 subcomments

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

by hvenev

1 subcomments

> 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).

by thevillagechief

2 subcomments

> 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.

by ChrisMarshallNY

1 subcomments

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.

by devin

1 subcomments

The more specific the "fact" is to the target, the better IMO.
- Bruce Schneier facts - https://www.schneierfacts.com/
- Doug McIlroy facts - https://github.com/mischief/9problems/blob/master/lib/dougfa...

by postscapes1

0 subcomment

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)

by m1ck

1 subcomments

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.

by dhruv3006

1 subcomments

https://static.googleusercontent.com/media/research.google.c...
To me this will remain his best work.

by linsomniac

1 subcomments

Reminds me of https://en.wikipedia.org/wiki/The_Story_of_Mel

by delichon

0 subcomment

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.

by bhickey

1 subcomments

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

by stogot

1 subcomments

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

by ripe

2 subcomments

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

by justinchen7

0 subcomment

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.

by leopoldj

0 subcomment

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.

by Bost

0 subcomment

The TheJeffDeanFacts repo contains no issues. (TRUE)

by VikingCoder

0 subcomment

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

0 subcomment

by anymouse123456

0 subcomment

My other favorite internal internal meme from that era was the Broccoli Man video, "I just want to serve 5 Terabytes."
https://www.youtube.com/watch?v=3t6L-FlfeaI

by nickstaggs

3 subcomments

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

by wernsey

0 subcomment

There is also a thread on Stack Exchange [1] for John Skeet facts, who has the most reputation there.
[1]: https://meta.stackexchange.com/questions/9134/jon-skeet-fact...

by shadowgovt

1 subcomments

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."

by furyofantares

1 subcomments

> 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...

by theodric

0 subcomment

This is the sort of thing that's perfect as a fortune file, so here you go: https://github.com/theodric/fortitude/tree/master/jeffdeanfa...

0 subcomment

by bananapub

0 subcomment

Someone should IARC the internal one.

by sidcool

0 subcomment

Jeff Dean achieved a Weismann score of 42.

by scrame

0 subcomment

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

by squigz

1 subcomments

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

by desi_ninja

0 subcomment

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

by Myrmornis

1 subcomments

Any recommendations for a talk by him to watch or something written by him to read?

by keybored

1 subcomments

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

by eatbitseveryday

0 subcomment

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

by saagarjha

3 subcomments

What’s Mustang? Web search?

by philipwhiuk

0 subcomment

See also https://meta.stackexchange.com/questions/9134/jon-skeet-fact...

by rednafi

0 subcomment

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

by esafak

2 subcomments

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.

by macybosts

0 subcomment

[dead]

by stefantalpalaru

0 subcomment

[dead]

by unit149

0 subcomment

[dead]

by m00dy

2 subcomments

can he beat llms ? don't think so.

by benzguo

0 subcomment

loved this so much i made a jeff dean persona for my AI: https://www.zo.computer/pub/persona/prs_WtLmiGHQmHqaMKIy

by lookingdesk

7 subcomments

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.

by jackblemming

1 subcomments

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 ;)