How do I optimise an AEM page with multiple custom components?

So I'm currently using AEM 6.5 for a demo website I'm trying to build. The use-case is, I need to pull content from a content management system(CMS) using restful API's to build this site. For this purpose, I've created a custom component that has a dropdown in its configuration for the different content categories available in the CMS. Now based on this content category and a unique id from the request parameters, I make a rest API call to my CMS to get data. 

I place this custom component at multiple places in my page for different content as needed. I use the Java backend (WCMUsePOJO) to make the API calls to my CMS. The issue I ran into is that, when I place multiple of these components on my page, the page slows down significantly. Is there any optimisation approach that you can suggest?

I'm also using the tab component on my page, so if there is any optimisation around that, it'll work too.