Though the microservice pattern divides the monolithic backend into multiple independent services, this may not be straightforward for the frontend. In the monolithic front approach, we keep the whole user interface in a single big frontend application that will talk to corresponding services through REST calls to perform tasks or to show data to the end user, as per the following diagram:

The clear benefits of this approach are an easy implementation and UI consistency across the application because everything is in a single place. On the downside, there may be a good amount of conflict regarding library versions, styling, and so on, as multiple teams are working on a single UI application.

Since everything is under one roof, it becomes harder to adopt changes as the application grows. Over a period of time, when business demand increases, it eventually becomes harder to maintain the application's UI as multiple teams spend most of their time solving problems. 

Choose this approach only when you are sure that the application is divided into just a few microservices with limited scope for growth in the future.