Trying to move service with API to private Subnet in AMAZON VPC

Question

The API we created is Public.

 Accessing from :

 api.domain.com

We recently moved the service to a private subnet with an Amazon VPC.
 The web application we are hosting on a public instance which communicates through API to this private instance. 

To access the API hosting on the private instance, how do we create an endpoint for it?

Guess, we can access it via XXX.XX.XXX.XXX which is the private IP address of the instance. 
However, we want to access it with a named endpoint such as api.domain.com. 
How to do this?
Is this method going to be scalable and reliable?
Is this as easy as editing the /etc/hosts file on the public instance?
XXX.XX.XXX.XXX api.domain.com

Answer 1

In such case, you can create a Private Hosted Zone into your Route53 in order to resolve your DNS within you VPC.

Create a Private Hosted Zone in Route53 to resolve DNS names within your VPC.

For more Details, you can check AWS Website mentioning the whole topic: https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/hosted-zones-private.html​

Cheers :)