Let's say I have two subdomains set on one droplet.

app.mydomain.com and api.mydomain.com

app.mydomain.com makes a request to api.mydomain.com which then returns data to app.mydomain.com. I've tested this and it works just fine, as expected.

Requests are a typical api type of query: http://api.mydomain.com/products?category=shoes and it returns a json response but I'm pretty sure that's not important.

What I'd like to know, is because both subdomains are on the same droplet, is there a more secure or more efficient way to allow requests to api.mydomain.com.

Further, if I should decide to move api.mydomain.com to another droplet and therefore another IP address, what then in terms of private requests?