Jeff Dean Facts
Chuck Norris facts of computer
Shamelessly stolen from
From time to time I’m looking for these, but I take
very long to find them. This is now a thing of the past.
- Jeff Dean proved that P=NP when he solved all NP
problems in polynomial time on a whiteboard.
Dean’s PIN is the last 4 digits of pi.
Jeff gives a seminar at Stanford, it’s so crowded Don
Knuth has to sit on the floor. (TRUE)
- Jeff Dean
once bit a spider, the spider got super powers and C++
- Once, in early 2002, when the index
servers went down, Jeff Dean answered user queries manually
for two hours. Evals showed a quality improvement of 5
- Jeff Dean got promoted to level 11 in a
system where max level is 10. (True.)
- Google Search
was Jeff Dean’s Noogler Project
- Jeff Dean has
punch card readability.
- Jeff Dean puts his pants on
one leg at a time, but if he had more than two legs, you
would see that his approach is actually O(log n)
- Jeff Dean acquired Sawzall readability after
writing 58 lines of Sawzall code. As part of his readability
review, he pointed out a flaw in the style guide which was
promptly corrected by the reviewer.
- Sanjay once
asked Jeff Dean if he could keep the entire web in his
memory. Due to the noise from his keyboard cooling fan, Jeff
Dean misheard slightly and wrote Mustang instead of simply
- Jeff Dean compiles and
runs his code before submitting, but only to check for
compiler and CPU bugs.
- Unsatisfied with constant
time, Jeff Dean created the world’s first O(1/n)
- Jeff Dean has binary readability.
- Jeff Dean has binary writability.
Jeff Dean goes on vacation, production services across
Google mysteriously stop working within a few days. This is
- Jeff Dean once shifted a bit so hard
it ended up on another computer.
- 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.
- You use 10% of your
brain. The other 90% is running one of Jeff’s
- Jeff Dean’s resume lists the
things he hasn’t done; it’s shorter that way.
- To Jeff Dean, "NP" means "No
- Jeff Dean wrote an O(n^2) algorithm
once. It was for the Traveling Salesman Problem.
- You don’t explain your work to Jeff Dean.
Jeff Dean explains your work to you.
Dean’s resume has so many accomplishments, it has a
table of contents.
- Jeff Dean was forced to invent
asynchronous APIs one day when he optimized a function so
that it returned before it was invoked.
- The rate at
which Jeff Dean produces code jumped by a factor of 40 in
late 2000 when he upgraded his keyboard to USB2.0.
- When Jeff Dean designs software, he first codes the
binary and then writes the source as documentation.
- Jeff Dean’s Peer Review is what got Larry
promoted to CEO.
- When God said: "Let there be
light!", Jeff Dean was there to do the code review.
- When Graham Bell invented the telephone, he saw a
missed call from Jeff Dean
- Compilers don’t
warn Jeff Dean. Jeff Dean warns compilers.
Dean doesn’t exist, he’s actually an advanced AI
created by Jeff Dean.
- Jeff Dean’s IDE
doesn’t do code analysis, it does code appreciation.
- Jeff Dean doesn’t use ECC memory. He
anticipates cosmic rays and uses them to improve
- Jeff Dean once failed a Turing test
when he correctly identified the 203rd Fibonacci number in
less than a second.
- Jeff Dean invented Bigtable so
that he would have a place to send his weekly snippets.
- On the zeroth day, Jeff Dean created God.
- Jeff Dean once implemented a web server in a single
printf() call. Other engineers added thousands of lines of
explanatory comments but still don’t understand
exactly how it works. Today that program is known as GWS.
- When Jeff has an ergonomic evaluation, it is for
the protection of his keyboard.
- Jeff Dean can beat
you at connect four. In three moves.
- Jeff Dean
invented BigTable because his resume was too big to fit
- Jeff Dean took the bite out of
- Chuck Norris can kill you. Jeff
Dean can kill -9 you.
- Jeff Dean can parse HTML with
a regular expression...correctly.
- When Jeff has
trouble sleeping, he Mapreduces sheep.
- When Jeff
Dean fires up the profiler, loops unroll themselves in fear.
- When your code has undefined behavior, you get a
seg fault and corrupted data. When Jeff Dean’s code
has undefined behavior, a unicorn rides in on a rainbow and
gives everybody free ice cream.
- Jeff doesn’t
sleep, he just sends SIGSUSPEND to the universe.
- Jeff got Java readability with only 8 lines of code
- Jeff Dean can instantiate abstract classes.
- gcc -O4 sends your code to Jeff Dean for a complete
- Jeff can recite 20,000 digits of pi in 5
hours. He doesn’t remember them; he just recomputes
them on the fly using only O(log n) space.
Dean remembers only one password. For each site, he
concatenates it with the site name, computes its SHA-256
hash, and then types the result.
- Jeff Dean is still
waiting for mathematicians to discover the joke he hid in
the digits of PI.
- There is no ’Ctrl’
key on Jeff Dean’s keyboard. Jeff Dean is always in
- Jeff Dean was born on December 31, 1969 at
11:48 PM. It took him twelve minutes to implement his first
- When Jeff Dean says "Hello
World", the world says "Hello Jeff".
- Jeff Dean can get 1s out of /dev/zero.
- Jeff Dean simply walks into Mordor.
Dean spent some 20% time on an AI project. That produced Urs
- Google once had to move out of a
datacenter after Jeff Dean accidentally compressed the index
so densely that a black hole was formed.
starts his programming sessions with "cat >
- The speed of light in a vacuum used
to be about 35 mph. Then Jeff Dean spent a weekend
- When Jeff Dean sends you a code
review, it’s because he thinks there’s something
in it you should learn.
- Jeff Dean does not sleep(),
- Jeff Dean invented MapReduce so he
could sort his fan mail.
- When Jeff Dean listens to
mp3s, he just cats them to /dev/dsp and does the decoding in
- Once Jeff Dean ordered a list, and the
list obeyed him.
- Chuck Norris is Jeff Dean’s
- When your code is killed by SIGJEFF,
it never runs again.
- Jeff Dean’s calendar
goes straight from March 31st to April 2nd; no one fools
- Jeff Dean never has the wrong number;
you have the wrong phone.
- Jeff Dean has exactly two
keys on his keyboard: "0" and "1."
- Errors treat Jeff Dean as a warning.
- Cricket matches used to take 5 days, until Jeff
- Jeff Dean’s watch displays
seconds since January 1st, 1970. He is never late.
- Jeff’s code is so fast the assembly code
needs three HALT opcodes to stop it.
preferred editor is Jeff Dean.
- Google: it’s
basically a Jeff Dean’s side project.
Dean has to unoptimize his code so that reviewers believe it
was written by a human.
- Websearch is just a large
unittest Jeff wrote for his real app.
- Jeff Dean
doesn’t need speakers or headphones. He just types
"cat *.mp3", glances at the screen, and his brain
decodes the music in the background while he works.
- Jeff Dean has Perl Readability. (TRUE)
- Jeff Dean quicksorts his laundry.
- The OR
ELSE construct had to be removed from ISO C after Jeff Dean
used it in Mustang and kernels started panicking in terror.
- Jeff Dean is not afraid of evil constructors. They
are afraid of him.
- Jeff Dean doesn’t write
bugs, just features you are unable to understand.
- When Jeff dean commits a code in his branch, the
master branch raises a merge request for his approval.