While42 is a French tech community for engineers and those with computer science degrees from French institutions. All members must be French speakers with technical backgrounds. The goal is for each local chapter to know each other personally, staying relatively small. Real connections between real people are emphasized over large size or scope.

1. About while42
0. FRENCH ONLY
TO BECOME A MEMBER OF WHILE42 YOU SHOULD BE EITHER A FRENCH TECH OR SOMEONE SPEAKING FRENCH AND HAVING A
COMPUTER SCIENCE DEGREE DELIVERED BY A FRENCH SCHOOL / UNIVERSITY.
1. TECH ENGINEERS ONLY
ALL WHILE42 MEMBERS ARE TECH ENGINEERS (DEVELOPERS, OPS, DEVOPS, SYS-ADMIN, INGENIEURS INFORMATICIENS, CTO ...)
AND/OR HAVE A DEGREE FROM A FRENCH ENGINEERING TECH SCHOOL (EPITECH,SUPINFO, EPITA, ...). THERE IS NO FILTER BY
DEGREE OR SCHOOL. YOU DO NOT HAVE TO HAVE A DEGREE TO JOIN AS SOON AS YOU ARE A TECH ENGINEER (AND FRENCH).
2. REAL NETWORK, REAL PEOPLE
EVERYBODY SHOULD KNOW EACH OTHERS IN EACH CHAPTER. THE GOAL IS NOT TO BE AS BIG AS POSSIBLE. WE DO NOT WANT TO BE
A BIG ORGANIZATION WHERE YOU DON’T KNOW WHO IS STANDING NEXT TO YOU. THUS WE WILL NEVER BE VERY BIG PER CHAPTER
AND EACH CHAPTER IS GROWING SLOWLY AFTER THE FIRST 50 MEMBERS.

2. You don’t know!
WHAT YOU DON’T KNOW MIGHT KILL YOUR SKILLS
AND KILL YOUR PROJECT

3. Performance = CPU?
Rarely is the processor the bottleneck, but so many
people look to 'tight loops' to speed up
performance when it's often an I/O issue.
If RAM was an F-18 Hornet with a max speed of
1,190 mph (more than 1.5x the speed of sound),
disk access speed is a banana slug with a top speed
of 0.007 mph.

4. Speed is important, isn’t it?
30 search answers (half a second increase in load
time) = -20% traffic and revenue for Google



All is ok < 0.1s
Flow of thought uninterrupted < 1.0s
10s < Attention focused lost
Google quote: “…we've decided to take site speed
into account in our search rankings”
Your users are stupid. Really stupid.
You are wrong: In 2009 Google tested 41 shades of
blue on a button to see which one was the most
effective at getting clicks

5. Programming != software engineering
• Many newer developers have difficulty in depicting
and understanding dependencies and
diagnosing/debugging them throughout a system
• It's no longer about processing data or writing your
program from a blank slate:
•
•
•
It's about teaching the novice how to use the interface first
then getting them familiar with what they need to add to the
generated code
Once you're by that, you can start to teach them how use the
programming language to help them get the task done.

6. What this?

7. What happened to the flowcharts?
• This is the 'No time to do it right, plenty of time to
do it over' method.
• It always takes longer.
• It's hard to resist the pressure of those who
demand 'Why aren't you coding yet?' but one
should.
• Stop assuming you would always remember every
line you wrote after your first year and always code
as if the person who ends up maintaining your
code is a violent psychopath who knows where you
live

8. In general
• DRY - Don’t repeat yourself
• Code Reuse is Good
• Avoid Creating a YAGNI (You aren’t going to need it)
• KISS (Keep it simple, stupid!)
• Do the simplest thing that could possibly work
• Don’t make me think
• Principle of least astonishment (side effects to avoid)
• Single Responsibility Principle
• Avoid Premature Optimization

9. Some sources
http://googleresearch.blogspot.com/2009/06/speed
-matters.html
http://googleblog.blogspot.com/2008/08/searchexperiments-large-and-small.html
http://code.google.com/speed/
http://glinden.blogspot.com/2006/11/marissamayer-at-web-20.html

10. Some sources
http://googleresearch.blogspot.com/2009/06/speed
-matters.html
http://googleblog.blogspot.com/2008/08/searchexperiments-large-and-small.html
http://code.google.com/speed/
http://glinden.blogspot.com/2006/11/marissamayer-at-web-20.html