time to tame the technologies!
Anne Collet
Citizens 3.0
Information & Communication Technologies
Software is at work Everywhere
Software is disrupting all industries
Software is Eating the World
2008
2009
1994
2004
1997
2009
why are tech startups
so popular today ?
the tech infrastructure is now
commoditization cost ↘︎
MATURE & affordable
↖︎
=>
a perfect environment for SAAS !
the Software as a Service business model
that many tech startups apply
a BM which relies heavily on the cloud infrastructure
SAAS products are highly scalable
for a Marginal COST +/- = 0
SAAS products are entirely dematerialized
SAAS products are easily Replicable
low barrier to entry
coding is fun, EASIER & powerful !
“Everybody should learn how to program a computer...
because it teaches you how to think.”
- Steve Jobs
“Coding is the 21st century literacy.”
- Neelie Kroes
“Don't just play on your phone. Program it.”
- Barack Obama
more than ever
'cause...
human end-users
should always
come first !
From passive consumers...
... become active users !
The Technologies
are evolving fast !
© BestReviews
Computers (= hardware )
are machines that
can be told what to do
programs (= software )
are written instructions that
define what we want the computer to do
program
computer
input
device
output
device
info in
info out
treatment
storage
In order to be executable by the computer,
instructions must be passed to it in
binary language
a sequence of 0s and 1s
it's a base-2 system
a bit (= binary digit)
can only take 2 possible values :
a byte is a set of 8 bits
hence the possibility to represent
2^8 (= 256) different "things"
(numbers, colors, characters,...)
128s 64s 32s 16s 8s 4s 2s 1s
0 0 0 0 0 0 0 1
the equivalent decimal number is : 1
numbers in binary
128s 64s 32s 16s 8s 4s 2s 1s
0 0 0 0 0 0 1 1
the equivalent decimal number is : 3
numbers in binary
128s 64s 32s 16s 8s 4s 2s 1s
1 0 1 0 0 0 1 1
the equivalent decimal number is : 163
numbers in binary
128s 64s 32s 16s 8s 4s 2s 1s
characters in binary
87
65
71
79
78
W
A
G
O
N
characters in binary
BINARY INSTRUCTIONS
1001101001001010100
programming languages
first_name = gets.chomp
vs
these 0s and 1s represent the discrete states
OFF, False, 0 Volts, no current flowing
ON, True, +Volts, the current flows
that must take the computer's core components
i.e. the transistors
once charged electronically, billions of tiny transistors...
will execute the logic we want
combined on a thin film of silicon, a semiconductor material,
to form an integrated circuit (aka microchip)
behind the various programming languages :
a common logic : algorithmics
algorithm :
a set of instructions
that precisely defines
a sequence of operations
to be performed
algorithmics :
the art of building a procedure
which can solve a problem
by breaking it down
into small logical steps
flowchart is one of the ways to represent an algorithm
The fizzbuzz example
0. Enumerate numbers until a defined stopper ('N')
1. Start by considering 'number' is equal to 1
2. If 'number' is a multiple of 3, say Fizz
3. If 'number' is a multiple of 5, say Buzz
4. If 'number' is a multiple of both, say FizzBuzz
5. Else say the current value of 'number'
6. Increment the value of 'number' by 1
7. Repeat until the value of 'number' is equal to 'N'
The fizzbuzz example
http://rosettacode.org/wiki/FizzBuzz
ASSEMBLY
The fizzbuzz example
http://rosettacode.org/wiki/FizzBuzz
RUBY
The fizzbuzz example
JAVA
The fizzbuzz example
JAVASCRIPT
development tools
development tools
text editor
terminal
online resources
ergonomic keyboard (Dvorak, Bépo,...)
development methodologies
Fact #1 : Developers are bad
at estimating work
Fact #2 : Business Owners are bad at explaining what they want
Fact #3 : We do not speak
the same language
=> Agile - 101
1. Split the work into small
user oriented tasks (User Stories)
2. Define time boxed
(short) iterations
3. End each iteration with a demo
4. Learn, iterate & improve
4. Learn, iterate & improve
The applications
web app
desktop app
mobile app
1
3
2
1. desktop application
a desktop application is
a program that runs locally on the user's computer
e.g. Microsoft Excel 2010
needs to
be installed on
the user's computer
strict hardware
requirements
(hard disk, RAM,...)
one version
for each OS
(Windows, Mac,...)
complicated
updates
no Internet connection needed to use it
often, basic
user interfaces
1. desktop application
2. mobile application
a mobile application is
a program that runs on a mobile device
and is exchanging data with a remote server via Internet
needs to
be installed on
the user's mobile device
e.g. Zoho Sheet Mobile
SENSORS
CPU (PERFORMANCe)
SHATTERED WORLD
+
- for iOS (Objective C or Swift)
- for Android (Java)
- for Windows Phone (C#)
=> 2 to 3 times the cost
of a web app !
3 very different families of
technologies / mobile OS :
SHATTERED WORLD
3. web application
a web application is
a program that runs on a remote web server
and is displayed on the user's computer's web browser
all you need is
a web browser on
the user's computer
e.g. Google Sheets
works even on users' devices with limited hardware capabilities
one single version of the app,
with continuous
development
seamless upgrade & easier maintenance
big problem for the user
if bad internet connection!
more interactive, media-rich user interfaces
3. web application
1. a computer
which tools to access a web page ?
a computer ?
1. a computer
2. an internet connection
which tools to access a web page ?
Internet (1969 - TCP/IP)
the global system of INTERconnected computer NETworks
Vint Cerf
Bob Kahn
Internet ?
TCP / IP
TCP / IP
an internet connection ?
ISP = Internet Service Provider
an internet connection ?
wired
wired
wireless
wireless
an internet connection ?
ISP = Internet Service Provider
in Belgium ?
via an Internet service provider (ISP)
an internet connection ?
ISP = Internet Service Provider
1. a computer
2. an internet connection
which tools to access a web page ?
3. a web browser
a web browser ?
www (1989 - HTTP)
the (World Wide) Web
Tim Berners-Lee
Robert Cailliau
www (1989 - HTTP)
the (World Wide) Web
accessible through a web browser
identifiable thanks to their unique URL/URI
connected together
via hyperlinks,
which allow us to surf
from one to another
a gigantic space of resources (images, HTML documents,...)
1. a computer
2. an internet connection
which tools to access a web page ?
3. a web browser
we're ready to surf the web ! *
* aka, navigate from one web page to another
by following hyperlinks
Web ≠ Internet
the World Wide Web is one of the many services
relying on the Internet infrastructure
Web ≠ Internet
the World Wide Web is one of the many services
relying on the Internet infrastructure
Web ≠ Internet
the World Wide Web is one of the many services
relying on the Internet infrastructure
DNS Resolver
www.google.com = IP address ?
url = IP address
Example :
www.google.com = 216.58.208.46
DNS servers hierarchy
DNS = Domain Name System
google.com = 216.58.208.46
url = IP address
webmaster
web visitors
web hosting
http request / http response
static website
(aka site vitrine)
http request / http response
dynamic website
(aka web application)
on the Client-side
( = the front-end part )
Front-end languages
content
+ structure
style
dynamism
+ usability
on the server-side
( = the back-end part )
back-end languages
The lego game
we could program everything from scratch...
...but it's boring & non productive
So we decided to
create re-usable blocks
of functionalities
pre-packaged libraries
within a specific framework
up to Build anything !
It has never been so easy to make software !
The API's
human to machine communication
but also mainly
machine to machine communication
thanks to API (application programming interfaces)
API
API
API
API
machines exchange structured content
{"richestPeople":[
{"firstName":"Bill", "lastName":"Gates", "value":"81"},
{"firstName":"Carlos", "lastName":"Slim", "value":"79"},
{"firstName":"Warren", "lastName":"Buffet", "value":"72"}
]}
what a machine likes to see
web services
more & more applications are created today
by calling the APIs of third-party web services
(Google maps, Facebook authentication,...)
web services
can be integrated into your application
by calling and consuming their API
web services
select the best ones
already widely tested & acclaimed
for their usability & functionality
Stripe (payment)
MailChimp (e-mailing)
Uber
application stack
web services
focus on your core business
and outsource the rest through APIs calls
API's are eating software
your learning process
learn to understand
Learn to experiment
Learn to build
online resources
events
online dev communities
offline dev communities
Thank you.
See you soon !
