Api max performance

Hi I have a project for location tracking. We get momentum from a certain number of users per day. What can be done on the software and hardware side to respond quickly to a demand of about 20 thousand users per day from a large number of users? For example, we get a position from a user at the moment, and these requests are picked up by the client, and while receiving these locations, millions of millions of requests are happening all the time. What needs to be done to solve them. The response times we have designed for a request at the moment of our design are 30 40 ms average, but this is quite low, but we need to follow a path in a high number of requests.