After a user signs in to the application, we will show a preview of their current expenses, including their total expenditure for the current month and how much they spent on the current date and the day before. This preview will be displayed to the end user, as shown in the following screenshot:

In order to implement this feature, we need to add a backend API that will process the existing expense data to return these three values, so it can be rendered in a React component. In the following sections, we will take a look at the implementation and integration of this API with a frontend view to complete this preview feature.