Design the Web Application

During the design process of your web application, the following considerations are likely to play a role in the design decisions that you make. The type of web application that you are designing determines the importance of each consideration.
The four considerations are:

• Security
• Scalability and reliability (availability)
• Search Engine Optimization (SEO)
• Localization

Security

Security is the level of importance and effort you are willing to put toward securing data and the administration features of your application. Every web application will require some level of security. Some web application types require much more focus on this consideration, such as e-commerce sites, where sensitive information may be stored.



Scalability and reliability (availability)
Scalability is concerned with the ability of your web application to scale when demand requires more resources. Reliability is concerned with the ability of your web application to survive resource outages, such as a single server failure.
Often scalability and reliability are closely linked, as the ability to recover from the loss of resources requires the ability of your web application to spread its processing across more than one single point of failure.


Search Engine Optimization (SEO)
SEO is concerned with the ease with which automated search engine crawlers can traverse your site. Automated search engine crawlers follow links that are available in your site and save key information about the content of your site on each page. This information is stored and is searchable by users who are interested in the topics that your site may cover.


Localization
Localization is concerned with providing your content to your users in multiple languages. Providing your content in several languages can expand your potential user base dramatically.