eXtreme Programming

Extreme Programming: What is it and basic principles?
Extreme programming is an agile development methodology that is primarily aimed at increasing productivity when developing a software project. Priority to jobs that give a direct result and in which the bureaucracy that may exist in the work environment is reduced.
We have 12 basic principles that are grouped into 4 different categories:
• Feedback.
• Continuous process rather than blocks.
• Shared intellectual property.
• Shared understanding.
Test principle: the first thing you should do is set a period of acceptance testing program, in which the inputs and outputs of the system will be defined. Basically it defines what should the software developed. As if it was a black box.
Planning: The clients (or his representative) write needs to define precisely the activities that the system must perform. At this stage a document containing user stories that form the release plan, which defines the delivery time of the application in order to receive feedback from the client will be created.
In-situ client: the client (or his representative) should be part of the development team. You will be given the power to determine the requirements of the application define the functionality and prioritize certain things. Thanks to this, there will be a strong interaction with programmers, thus reducing communication time and the amount of documentation to write. The customer will be with the team throughout the project development process.
Pair-programming: These points with the above are the most radical of this methodology. It is to write code in pairs sharing a single machine. According to the experiments already carried out on this method, better and more consistent applications at equal or lower cost occur.
Continuous integration: is gradually implementing new software features. Instead of creating stable versions according to a schedule previously performed, programmers meet your code and rebuild the project several times a day if necessary.
Refactoring: by constantly removing duplicate code and / or inefficient programming teams improve the system design. The code is continuously evaluated to provide the highest possible quality.
Small deliveries: the product is tested in a real environment by placing a simple production system which will be updated quickly, ie, every 2 weeks (maximum 3) the software will be put into production.

Simple design: the best program is one that meets the requirements and simpler. It is important to provide software that meets the needs of a client. No more no less.
Metaphor: expresses the evolutionary view of the project and defines the objectives of the system through a story.
Collective ownership of code: the code has shared ownership. Nobody owns anything, even what he has developed. All programmers are “owners” of all the code. According to this methodology, the more programmers is working on a piece of code, fewer errors will.
Programming standard defines the rules for writing and documenting code, and how the different pieces of code developed by different teams communicate. The aim of this is that it seems that the code has been written by a single person.

–Slimane Zouggari