9 ms·

The Jeff Dean Facts

558 points by ravenical 9mo ago

thevillagechief 9mo 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.
- scottlamb 9mo 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.
  - flir 9mo ago
    I would definitely give up my seat to Don Knuth.
    - scottlamb 9mo ago
      In theory I would too, but I was also on the floor, and believe it or not I didn't notice Don Knuth was there until after the talk had started.
  - nooks 9mo ago
    Friends and I nabbed front-row seats to the Munroe talk; after a time we were asked to take seats a few rows back to make room for Knuth and others. He definitely did not sit on the floor.
    - scottlamb 9mo ago
      Well, that shows what my 90% sure memory is worth. I sit corrected.
  - svat 9mo ago
    FWIW the XKCD talk at Google is here (wow, 18 years ago! I remember watching this video when it was posted): https://www.youtube.com/watch?v=zJOS0sV2a24 https://www.youtube.com/watch?v=zJOS0sV2a24 (Knuth comes up to ask a question at 21:30) (Can't tell from the video where he was sitting otherwise, though there are definitely at least some people sitting on the floor.)
- dekhn 9mo 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.
stogot 9mo ago
I didn’t think I’d laugh, but a few of these cheered me up. Laughter is such a good medicine.
- callumprentice 9mo ago
  Agreed! I felt the same way but sitting here with my morning coffee chuckling away. A good start to the day.
VikingCoder 9mo ago
In an alternate universe, pi is rational, and Jeff Dean is not.
saagarjha 9mo ago
What’s Mustang? Web search?
- bananapub 9mo ago
  yes
- mike_hearn 9mo ago
  It is or was the serving component of the main index. The part that does the posting list intersections and lookups.
- utopcell 9mo ago
  Web Search Serving. Many generations ago.
ChrisMarshallNY 9mo 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 9mo ago
  What I’ve found is some really average developers thinking they’re Jeff Dean, or at least have that attitude.
esafak 9mo 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 9mo 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.
  - shemnon42 9mo ago
    Everyone at Google has imposter syndrome. If you don't, this is how they make sure you get it.
  - zerr 9mo ago
    Wasn't Peter Norvig one of the key people behind Google Search? Would it be correct to say that scientists did the research, maybe reference implementations in Lisp or Python, and later Jeff Dean did the actual C++ production?
    - dekhn 9mo ago
      Peter worked on search, yes. I think he mainly focused on quality. See his comment on "Managing Gigabytes" (https://www.amazon.com/review/R33MIMY7A7C2H8/ref=cm_cr_srp_d_rdp_perm?ie=UTF8&ASIN=1558605703 https://www.amazon.com/review/R33MIMY7A7C2H8/ref=cm_cr_srp_d...) which was an early reference for the compression techniques used to make search fast. The way jeff described it was that there was a very early contingent who took Larry's original code and made a production system out of it, but it wasn't very good- the indexer basically had to be run all the way through without errors to make a new index- and that was delaying a release of a fresh new index, so results were getting stale. At that point Jeff "invented" mapreduce (the shuffle stage was Sanjay) and wrote the new indexer and the search engine as well. I'm not aware of any LISP implementation of the Google search engine; if there was one, it would have been extremely early, like in the stanford days, I think.
andy99 9mo 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 9mo 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.
  - mock-possum 9mo ago
    I vaguely remember another instance of this around a guy in the army - I forgot if it was at boot camp or what the rank was, but it was something along the lines of “things I’m no longer allowed to do” and just had a bunch of silly military joke/prank type things… man I wonder if I could dig that up again, I think it might have been late 90s internet.
    - OrsonSmelles 9mo ago
      That would be Skippy's List[0], which as far as I know is the seminal work in the genre (at least on the internet). I originally learned about it through a (rather less compact) version about someone's D&D crimes[1], which was closer to my cultural wheelhouse, but the original holds up even if you have to google some phrases. [0] https://skippyslist.com/list/ https://skippyslist.com/list/ [1] https://theglen.livejournal.com/16735.html https://theglen.livejournal.com/16735.html
      - 0xWTF 9mo ago
bananapub 9mo ago
Someone should IARC the internal one.
dust-jacket 9mo ago
OK "Jeff Dean once shifted a bit so hard it ended up on another computer" got a proper chuckle from me
- chihuahua 9mo ago
  This is the basis for the software that allows you to use a single mouse to control a mouse pointer on several computers.
scottlamb 9mo 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
- jeffbee 9mo ago
  The other thing that ran under Jeff's desk for a long time was Code Search, the old one.
  - shadowgovt 9mo ago
    I remember this. He went on vacation and since he wasn't available to login, code search indexing went down for a bit.
- kentonv 9mo 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.
squigz 9mo ago
"When God said: "Let there be light!", Jeff Dean was there to do the code review."
- dekhn 9mo ago
  I think this makes more sense: "When God said: "Let there be light!", Jeff Dean said "LGTM, Approve"
m1ck 9mo 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 9mo ago
  I have been laughing about the PIN/pi joke over and over for the past 24 hours.
m00dy 9mo ago
can he beat llms ? don't think so.
- dekhn 9mo 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 9mo ago
  Anyone of modest competence can beat LLMs.
  - cindyllm 9mo ago
    [dead]
macybosts 9mo ago
[dead]
kentonv 9mo 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).
- bummy_commenter 9mo ago
  What makes it feel a little racist?
  - Lerc 9mo ago
    >"Jeff Dean Facts" sort of rolls off the tongue easier that "Sanjay Ghemawat Facts" The reason it rolls off the tongue easier is because of the familiarity with names of that form. It is making a choice to favour a personal cultural similarity. It clearly wasn't done with malice, but being reflective about it and noticing that it happened is a good thing. When people talk about privilege, this is a large part of what people mean. There's no intended bias, it is just an honest choice, but all of our choices are based upon our opinions that will inherently have biases of some sort. One factor of privilege is when those choices disproportionately fall your way because decisions end up being made by people who you share a cultural upbringing with. Their intuitive decisions value what you value. Sometimes the only way you can deal with that is by acknowledging your intuitions contain that implicit bias and dispassionately try and balance them as best you can.
deleted 9mo ago
[deleted]
keybored 9mo ago
Guy happens to be the lead of Google AI right now.
- lysace 9mo 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://en.wikipedia.org/wiki/Google_DeepMind https://research.google/people/jeff/ 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.
nickstaggs 9mo 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
- billbrown 9mo ago
  He's the Chuck Norris of StackOverflow, maybe.
- dysoco 9mo 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.
  - Sesse__ 9mo ago
    Jon Skeet was very much a local hero on StackOverflow, and on StackOverflow only.
    - tiffanyh 9mo ago
      Claude & Codex are still learning from Jon Skeet.
- freeCandy 9mo ago
  To me, the Chuck Norris of programming has to be Fabrice Bellard
linsomniac 9mo ago
Reminds me of https://en.wikipedia.org/wiki/The_Story_of_Mel https://en.wikipedia.org/wiki/The_Story_of_Mel
- shagie 9mo ago
  As I write this, catb is not serving promptly... so https://users.cs.utah.edu/~elb/folklore/mel.html https://users.cs.utah.edu/~elb/folklore/mel.html I also recommend Monktoberfest 2016: Bryan Cantrill - Oral Tradition in Software Engineering : https://youtu.be/4PaWFYm0kEw?si=nqfxSae52-89x5Ye&t=653 https://youtu.be/4PaWFYm0kEw?si=nqfxSae52-89x5Ye&t=653
lookingdesk 9mo 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.
- whynotminot 9mo ago
  As far as I can tell, no one seems to think much of value was lost.
  - shadowgovt 9mo ago
    It turns out when you usher the dissenters out of the room, you hear a lot less dissent.
    - whynotminot 9mo ago
      It’s not like they were summarily executed. They are much freer now outside of corporate control to speak their minds as they please. The only real question is if anyone deems them worth listening to.
      - shadowgovt 9mo ago
        I mean, I follow them. Their problem domain is pretty niche and they're pretty technical on it so I don't doubt their traction is mostly academics.
  - keeganpoppen 9mo ago
    even at the time that was the verdict
  - foolfoolz 9mo ago
    ai ethics was/is useless. it felt a lot like the movie industry of the 1930s saying they will police themselves just to keep any bigger regulator away
    - 9mo ago
benzguo 9mo ago
loved this so much i made a jeff dean persona for my AI: https://www.zo.computer/pub/persona/prs_WtLmiGHQmHqaMKIy https://www.zo.computer/pub/persona/prs_WtLmiGHQmHqaMKIy
justinchen7 9mo 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.
dhruv3006 9mo ago
https://static.googleusercontent.com/media/research.google.com/en//archive/mapreduce-osdi04.pdf https://static.googleusercontent.com/media/research.google.c... To me this will remain his best work.
- hxtk 9mo ago
  Even with the ellipsized link I knew you were talking about one of a few things because the link shows up as `:visited` for me... had to be either BigTable, MapReduce, or Spanner. All good reads.
leopoldj 9mo 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.
bhickey 9mo ago
I once mailed a CL to Sanjay. He replied, "This is outside of my expertise. Can you send it to Jeff?"
- seanmcdirmid 9mo 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.
  - acoster 9mo ago
    IME Sanjay responds to CLs way faster than I expected.
    - seanmcdirmid 9mo ago
      I've never had in for a review at google, I think it only happens if you change something very top level. I did an internship under him the summer before he joined Google at Dec/Compaq SRC though. I learned a lot of tricks from him then (like using graphviz to print out compiler graphs to do debugging).
      - bhickey 9mo ago
        I was messing around with one of the old RNGs, trying to kill off a few thousand tests that depended on its exact output sequence.
philipwhiuk 9mo ago
See also https://meta.stackexchange.com/questions/9134/jon-skeet-facts https://meta.stackexchange.com/questions/9134/jon-skeet-fact...
postscapes1 9mo 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)
devin 9mo ago
The more specific the "fact" is to the target, the better IMO. - Bruce Schneier facts - https://www.schneierfacts.com/ https://www.schneierfacts.com/ - Doug McIlroy facts - https://github.com/mischief/9problems/blob/master/lib/dougfacts https://github.com/mischief/9problems/blob/master/lib/dougfa...
- never_inline 9mo ago
  > Bruce Schneier intercepts all your internal monologues by a man-in-the-middle attack.
shadowgovt 9mo 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 9mo 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.
pss314 9mo ago
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-that-made-google-huge https://www.newyorker.com/magazine/2018/12/10/the-friendship...
stefantalpalaru 9mo ago
[dead]
rednafi 9mo ago
Another one I have heard is "Jeff Dean's stare can fix bitrot"
jackblemming 9mo 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 9mo ago
  Let's be honest: you don't have the slightest idea about what you're talking about.
  - jackblemming 9mo ago
    TensorFlow lost because it’s an inferior API and dev UX. Hate to break it to you. I’m sure it got Jeff a lot of high-fives because it’s very complicated though!
hvenev 9mo 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 9mo 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.
ripe 9mo ago
What does "readability" mean? It's mentioned in several of these jokes: "binary readability", etc.
- bubblicious 9mo ago
  readability grants a code reviewer the power to approve changes in a specific language
  - shemnon42 9mo ago
    I was wondering if someone was going to ask. It's the most bizzare aspect of code reviews at Google. And "Readability" doesn't mean you are good at a language, it means you are good at it in the way Google uses it. C++ readability is the poster child of this. Borgcron, not so much.
    - hn_go_brrrrr 9mo ago
      Did you mean Borgmon? Borgcron is just GCL. Sawzall is another good example of an unreadable language.
  - sowbug 9mo ago
    A bit more detail: long ago, before the time of the Great Brace War, people wrote code using all sorts of styles: tabs/spaces, short or long variable/function names, Hungarian notation or not, comments or not, long blocks or short, and so on. You could often tell which of your teammates wrote a block of code simply by newline usage. This made it hard to read and contribute code in a less familiar part of the codebase. Google mitigated this problem at scale by introducing the concept of "readability" for each language (C++, Java, and Python, simpler times). If you had readability, you could approve another person's change for that language. If you didn't, you could still review the code, but the reviewee also had to go find someone else with readability. After you'd accumulated a certain number of commits in a language, you could try to get your own readability by bundling up your CLs (changelists) and submitting them to the readability queue, where a certain group of senior people with readability would evaluate whether your code was sufficiently idiomatic. This process could take months, or even years if you didn't write much in a particular language. In any event, it felt like a real achievement to get readability. The upshot of all this was that most code at Google felt authorless in a good way: if you knew and expected Google style, all the codebase felt the same, and you could concentrate on the logic flow rather than the regional dialect. And needless to say all the energy wasted on whose style was best was squelched in the readability queue. This is all past tense because I last wrote code for Google more than 10 years ago, and I'm sure the process has changed since then. Code formatters, shared editor defaults, and presubmit checks have surely automated away a lot of the toil, and there's much less of a monorepo culture these days, so there are probably more style dialects (in addition to many, many more permitted languages).
desi_ninja 9mo ago
We need a Dave Cutler facts equivalent too. But the ppl who could have made this are probably retired or
furyofantares 9mo 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 9mo ago
  Those are still O(1)
  - furyofantares 9mo ago
    Right, lol
deleted 9mo ago
[deleted]
theodric 9mo ago
This is the sort of thing that's perfect as a fortune file, so here you go: https://github.com/theodric/fortitude/tree/master/jeffdeanfacts https://github.com/theodric/fortitude/tree/master/jeffdeanfa...
Bost 9mo ago
The TheJeffDeanFacts repo contains no issues. (TRUE)
Myrmornis 9mo ago
Any recommendations for a talk by him to watch or something written by him to read?
- Keyframe 9mo ago
  yes on a serious note, this recent-ish interview on AI is illuminating https://www.youtube.com/watch?v=dq8MhTFCs80 https://www.youtube.com/watch?v=dq8MhTFCs80
sidcool 9mo ago
Jeff Dean achieved a Weismann score of 42.
wernsey 9mo ago
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-facts https://meta.stackexchange.com/questions/9134/jon-skeet-fact...
unit149 9mo ago
[dead]
delichon 9mo 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.
eatbitseveryday 9mo ago
I’m not sure I’m comfortable idolizing someone living like this
anymouse123456 9mo ago
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 https://www.youtube.com/watch?v=3t6L-FlfeaI
scrame 9mo 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 https://www.youtube.com/watch?v=--EGyU57efY

558 points by ravenical 9mo 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.

scottlamb 9mo 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.
- flir 9mo ago
  I would definitely give up my seat to Don Knuth.
  - scottlamb 9mo ago
    In theory I would too, but I was also on the floor, and believe it or not I didn't notice Don Knuth was there until after the talk had started.
- nooks 9mo ago
  Friends and I nabbed front-row seats to the Munroe talk; after a time we were asked to take seats a few rows back to make room for Knuth and others. He definitely did not sit on the floor.
  - scottlamb 9mo ago
    Well, that shows what my 90% sure memory is worth. I sit corrected.
- svat 9mo ago
  FWIW the XKCD talk at Google is here (wow, 18 years ago! I remember watching this video when it was posted): https://www.youtube.com/watch?v=zJOS0sV2a24 https://www.youtube.com/watch?v=zJOS0sV2a24 (Knuth comes up to ask a question at 21:30) (Can't tell from the video where he was sitting otherwise, though there are definitely at least some people sitting on the floor.)
dekhn 9mo 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.

stogot 9mo ago

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

callumprentice 9mo ago
Agreed! I felt the same way but sitting here with my morning coffee chuckling away. A good start to the day.

VikingCoder 9mo ago

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

saagarjha 9mo ago

What’s Mustang? Web search?

bananapub 9mo ago
yes
mike_hearn 9mo ago
It is or was the serving component of the main index. The part that does the posting list intersections and lookups.
utopcell 9mo ago
Web Search Serving. Many generations ago.

ChrisMarshallNY 9mo 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 9mo ago
What I’ve found is some really average developers thinking they’re Jeff Dean, or at least have that attitude.

esafak 9mo 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 9mo 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.
- shemnon42 9mo ago
  Everyone at Google has imposter syndrome. If you don't, this is how they make sure you get it.
- zerr 9mo ago
  Wasn't Peter Norvig one of the key people behind Google Search? Would it be correct to say that scientists did the research, maybe reference implementations in Lisp or Python, and later Jeff Dean did the actual C++ production?
  - dekhn 9mo ago
    Peter worked on search, yes. I think he mainly focused on quality. See his comment on "Managing Gigabytes" (https://www.amazon.com/review/R33MIMY7A7C2H8/ref=cm_cr_srp_d_rdp_perm?ie=UTF8&ASIN=1558605703 https://www.amazon.com/review/R33MIMY7A7C2H8/ref=cm_cr_srp_d...) which was an early reference for the compression techniques used to make search fast. The way jeff described it was that there was a very early contingent who took Larry's original code and made a production system out of it, but it wasn't very good- the indexer basically had to be run all the way through without errors to make a new index- and that was delaying a release of a fresh new index, so results were getting stale. At that point Jeff "invented" mapreduce (the shuffle stage was Sanjay) and wrote the new indexer and the search engine as well. I'm not aware of any LISP implementation of the Google search engine; if there was one, it would have been extremely early, like in the stanford days, I think.

andy99 9mo 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 9mo 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.
- mock-possum 9mo ago
  I vaguely remember another instance of this around a guy in the army - I forgot if it was at boot camp or what the rank was, but it was something along the lines of “things I’m no longer allowed to do” and just had a bunch of silly military joke/prank type things… man I wonder if I could dig that up again, I think it might have been late 90s internet.
  - OrsonSmelles 9mo ago
    That would be Skippy's List[0], which as far as I know is the seminal work in the genre (at least on the internet). I originally learned about it through a (rather less compact) version about someone's D&D crimes[1], which was closer to my cultural wheelhouse, but the original holds up even if you have to google some phrases. [0] https://skippyslist.com/list/ https://skippyslist.com/list/ [1] https://theglen.livejournal.com/16735.html https://theglen.livejournal.com/16735.html
    - 0xWTF 9mo ago

bananapub 9mo ago

Someone should IARC the internal one.

dust-jacket 9mo ago

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

chihuahua 9mo ago
This is the basis for the software that allows you to use a single mouse to control a mouse pointer on several computers.

scottlamb 9mo 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

jeffbee 9mo ago
The other thing that ran under Jeff's desk for a long time was Code Search, the old one.
- shadowgovt 9mo ago
  I remember this. He went on vacation and since he wasn't available to login, code search indexing went down for a bit.
kentonv 9mo 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.

squigz 9mo ago

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

dekhn 9mo ago
I think this makes more sense: "When God said: "Let there be light!", Jeff Dean said "LGTM, Approve"

m1ck 9mo 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 9mo ago
I have been laughing about the PIN/pi joke over and over for the past 24 hours.

m00dy 9mo ago

can he beat llms ? don't think so.

dekhn 9mo 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 9mo ago
Anyone of modest competence can beat LLMs.
- cindyllm 9mo ago
  [dead]

macybosts 9mo ago

[dead]

kentonv 9mo 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).

bummy_commenter 9mo ago
What makes it feel a little racist?
- Lerc 9mo ago
  >"Jeff Dean Facts" sort of rolls off the tongue easier that "Sanjay Ghemawat Facts" The reason it rolls off the tongue easier is because of the familiarity with names of that form. It is making a choice to favour a personal cultural similarity. It clearly wasn't done with malice, but being reflective about it and noticing that it happened is a good thing. When people talk about privilege, this is a large part of what people mean. There's no intended bias, it is just an honest choice, but all of our choices are based upon our opinions that will inherently have biases of some sort. One factor of privilege is when those choices disproportionately fall your way because decisions end up being made by people who you share a cultural upbringing with. Their intuitive decisions value what you value. Sometimes the only way you can deal with that is by acknowledging your intuitions contain that implicit bias and dispassionately try and balance them as best you can.

deleted 9mo ago

[deleted]

keybored 9mo ago

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

lysace 9mo 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://en.wikipedia.org/wiki/Google_DeepMind https://research.google/people/jeff/ 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.

nickstaggs 9mo 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

billbrown 9mo ago
He's the Chuck Norris of StackOverflow, maybe.
dysoco 9mo 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.
- Sesse__ 9mo ago
  Jon Skeet was very much a local hero on StackOverflow, and on StackOverflow only.
  - tiffanyh 9mo ago
    Claude & Codex are still learning from Jon Skeet.
freeCandy 9mo ago
To me, the Chuck Norris of programming has to be Fabrice Bellard

linsomniac 9mo ago

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

shagie 9mo ago
As I write this, catb is not serving promptly... so https://users.cs.utah.edu/~elb/folklore/mel.html https://users.cs.utah.edu/~elb/folklore/mel.html I also recommend Monktoberfest 2016: Bryan Cantrill - Oral Tradition in Software Engineering : https://youtu.be/4PaWFYm0kEw?si=nqfxSae52-89x5Ye&t=653 https://youtu.be/4PaWFYm0kEw?si=nqfxSae52-89x5Ye&t=653

lookingdesk 9mo 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.

whynotminot 9mo ago
As far as I can tell, no one seems to think much of value was lost.
- shadowgovt 9mo ago
  It turns out when you usher the dissenters out of the room, you hear a lot less dissent.
  - whynotminot 9mo ago
    It’s not like they were summarily executed. They are much freer now outside of corporate control to speak their minds as they please. The only real question is if anyone deems them worth listening to.
    - shadowgovt 9mo ago
      I mean, I follow them. Their problem domain is pretty niche and they're pretty technical on it so I don't doubt their traction is mostly academics.
- keeganpoppen 9mo ago
  even at the time that was the verdict
- foolfoolz 9mo ago
  ai ethics was/is useless. it felt a lot like the movie industry of the 1930s saying they will police themselves just to keep any bigger regulator away
  - 9mo ago

benzguo 9mo ago

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

justinchen7 9mo 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.

dhruv3006 9mo ago

https://static.googleusercontent.com/media/research.google.com/en//archive/mapreduce-osdi04.pdf https://static.googleusercontent.com/media/research.google.c... To me this will remain his best work.

hxtk 9mo ago
Even with the ellipsized link I knew you were talking about one of a few things because the link shows up as `:visited` for me... had to be either BigTable, MapReduce, or Spanner. All good reads.

leopoldj 9mo 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.

bhickey 9mo ago

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

seanmcdirmid 9mo 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.
- acoster 9mo ago
  IME Sanjay responds to CLs way faster than I expected.
  - seanmcdirmid 9mo ago
    I've never had in for a review at google, I think it only happens if you change something very top level. I did an internship under him the summer before he joined Google at Dec/Compaq SRC though. I learned a lot of tricks from him then (like using graphviz to print out compiler graphs to do debugging).
    - bhickey 9mo ago
      I was messing around with one of the old RNGs, trying to kill off a few thousand tests that depended on its exact output sequence.

philipwhiuk 9mo ago

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

postscapes1 9mo 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)

devin 9mo ago

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

never_inline 9mo ago
> Bruce Schneier intercepts all your internal monologues by a man-in-the-middle attack.

shadowgovt 9mo 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 9mo 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.

pss314 9mo ago

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-that-made-google-huge https://www.newyorker.com/magazine/2018/12/10/the-friendship...

stefantalpalaru 9mo ago

[dead]

rednafi 9mo ago

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

jackblemming 9mo 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 9mo ago
Let's be honest: you don't have the slightest idea about what you're talking about.
- jackblemming 9mo ago
  TensorFlow lost because it’s an inferior API and dev UX. Hate to break it to you. I’m sure it got Jeff a lot of high-fives because it’s very complicated though!

hvenev 9mo 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 9mo 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.

ripe 9mo ago

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

bubblicious 9mo ago
readability grants a code reviewer the power to approve changes in a specific language
- shemnon42 9mo ago
  I was wondering if someone was going to ask. It's the most bizzare aspect of code reviews at Google. And "Readability" doesn't mean you are good at a language, it means you are good at it in the way Google uses it. C++ readability is the poster child of this. Borgcron, not so much.
  - hn_go_brrrrr 9mo ago
    Did you mean Borgmon? Borgcron is just GCL. Sawzall is another good example of an unreadable language.
- sowbug 9mo ago
  A bit more detail: long ago, before the time of the Great Brace War, people wrote code using all sorts of styles: tabs/spaces, short or long variable/function names, Hungarian notation or not, comments or not, long blocks or short, and so on. You could often tell which of your teammates wrote a block of code simply by newline usage. This made it hard to read and contribute code in a less familiar part of the codebase. Google mitigated this problem at scale by introducing the concept of "readability" for each language (C++, Java, and Python, simpler times). If you had readability, you could approve another person's change for that language. If you didn't, you could still review the code, but the reviewee also had to go find someone else with readability. After you'd accumulated a certain number of commits in a language, you could try to get your own readability by bundling up your CLs (changelists) and submitting them to the readability queue, where a certain group of senior people with readability would evaluate whether your code was sufficiently idiomatic. This process could take months, or even years if you didn't write much in a particular language. In any event, it felt like a real achievement to get readability. The upshot of all this was that most code at Google felt authorless in a good way: if you knew and expected Google style, all the codebase felt the same, and you could concentrate on the logic flow rather than the regional dialect. And needless to say all the energy wasted on whose style was best was squelched in the readability queue. This is all past tense because I last wrote code for Google more than 10 years ago, and I'm sure the process has changed since then. Code formatters, shared editor defaults, and presubmit checks have surely automated away a lot of the toil, and there's much less of a monorepo culture these days, so there are probably more style dialects (in addition to many, many more permitted languages).

desi_ninja 9mo ago

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

furyofantares 9mo 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 9mo ago
Those are still O(1)
- furyofantares 9mo ago
  Right, lol

deleted 9mo ago

[deleted]

theodric 9mo ago

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

Bost 9mo ago

The TheJeffDeanFacts repo contains no issues. (TRUE)

Myrmornis 9mo ago

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

Keyframe 9mo ago
yes on a serious note, this recent-ish interview on AI is illuminating https://www.youtube.com/watch?v=dq8MhTFCs80 https://www.youtube.com/watch?v=dq8MhTFCs80

sidcool 9mo ago

Jeff Dean achieved a Weismann score of 42.

wernsey 9mo ago

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

unit149 9mo ago

[dead]

delichon 9mo 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.

eatbitseveryday 9mo ago

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

anymouse123456 9mo ago

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 https://www.youtube.com/watch?v=3t6L-FlfeaI

scrame 9mo 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 https://www.youtube.com/watch?v=--EGyU57efY