Cloud based applications whether in the Financial domain or otherwise, implement a logical separation between the user interface that is presented to the customer and the programs that fetch the data from the database, perform computation and return a result set. The User Interface (UI) is usually built using graphical components while the  programs that perform computations are built using a framework that exposes them as an API (Application Programming Interface). The coupling between the UI and API is asynchronous i.e. the UI sends a request and gets a response.