Improve API Request Thruput for Enterprise Application

I am currently writing an integration between BOX and an already existing website. The intended purpose is to allow the user to request a file on the website, at which point the integration would go find the file in box and then serve the file to the user through the site. 

I've created an enterprise integration application using JWT Server authentication and built some simple unit tests. It seems that when a high volume of requests go through the API seems to respond slowly (100 calls to the GetInformationAsync method takes around 20 seconds).

Given the size of our user base I have some concerns about thruput and users potentially having to wait long periods of time to get their files. Is there a recommended way for me to improve response times or potentially a different set of API's that I should be using?

Thanks!