How to add a load balancer at a later stage and re-configure DNS without downtime?
<p>Say I deploy an API, the database etc. to a t2.micro EC2 instance to serve traffic for the period of prototyping and beta testing. Let's say the domain pointing to the API is api.exampleapp.com. </p>

<p>Now traffic begins to grow beyond the instance's limits and we deploy the API to a bunch of instances that we want to stand behind a load balancer. After setting the fleet up, how do we make api.exampleapp.com point now to the load balancer's IP address so that traffic is served by the newly launched instances without any downtime? Is this possible at all? Or with minimal downtime? Or is this approach of starting up with a new API itself faulty? </p>