Managing test cases and suits for - API's


While exploring the tool for testing web services i find it very easy and interactive to use. At the same time it reduces the pain of writing test cases for all my end points with all very possible combination checks for my responses/requests to the service.

On the other hand i am wondering and curious to know how to manage my test cases for all these endless endpoints under my project.

For instance
a). I have one service with say 10 controllers and to each controller we have ‘n’ number of endpoints.
b). We have ‘n’ number of positive and negative set of test cases need to be verified for each endpoint.
c). These services are consumed by different web portals. - i can create different projects for that.

So point a and b are the black corners for me at the moment.

Please suggest.

A happy Katalon user.