Application Layer

This is where behind-the-scenes work is done after data is received from frontend layer.

This layer comprises of a section which will contain code for entire business logic based on your application and the workflow.

From SRE perspective, I would like to bring a few points that you need to consider

when you look at the application layer. First, which we already talked about, that it will collect data from frontend and process it as per the business logic.

If your application connects with another application, which is usually done by mechanized id/password or through certificate, those details will be stored in property file of your application layer.

The application code will fetch the ID password or certificate detail from the property file, complete

the authentication and establish the connection with the interface for further processing.

The workflow manager will act based on business logic.

For example, in a banking application, the app layer will be processing the financial transaction.

The app layer off a shopping website will move your selected order to cart or connect you to a banking portal,

which is an interface for payment, etc..

After completion of your shopping, you get email or text message. Here, the logic of interaction with

the interface and decision making to send email or text message will be acted by the workflow manager

based on information coming from the business logic.

All these different set of processing, workflow information, response we get from interface and action

performed on customer data, everything will be stored in database. Depending upon what type of data it is,

for example, customer login ID password, which you use to authenticate at the frontend layer will

be stored in a database in encrypted form or the customer address, phone number, etc. These are all

stored in encrypted form.

In short, all SPI data that is sensitive parameter index are stored in encrypted form.

It is compliance policy which every company uses for protecting its customer identity theft.

This is all that happens in application layer. Overall, to summarize, the app layer is same like human body.The brain of the body is business logic, which continuously gives you signal based on what your body parts are, that is workflow manager processes and stores each and every detail in the database.