How to make the utilization of multple Microservices fast?

Solution for How to make the utilization of multple Microservices fast?
is Given Below:

Suppose we have a microservice architecture with many different services. We also have an app that
gets data from these different services. The app runs on both Android and IOS. The problem we face
is that when we start this app, the first page on the app needs to show data that comes from 15
different microservices. The time to retrieve all this data from all 15 microservices takes 10 seconds,
which is too slow and not acceptable.
The app should get all the required data as fast as possible. It should not take more than 2.5 seconds
to retrieve all necessary data.
How can we solve this problem?