How do I setup distinct dev & production droplets with a single domain name?

Hello there,

I am fairly new to using Digital Ocean and need some advice/help in setting up a development - production environment with a single domain name.

I already have a droplet in SGP1 which I have been using as my production droplet. My domain currently points to SGP1

SGP1 has been configured with GSuite and AWS.

I plan on buying another droplet in Bangalore and making this the production droplet to handle the live traffic and make SGP1 the development/staging droplet. To do this I plan on taking a snapshot and then deploy it on the new droplet. Then change the naming servers with my domain provider.

Also, I want to access the all the resources in prod with - www.domain.com, and the resources in dev droplet preferably with a subdomain say - dev.domain.com alternatively I’m open to access it directly via an IP.

What sort of changes will I have to do in order to make Gsuite & AWS work seamlessly? Where and what kind of changes need to be made?

How do I achieve the routing to dev.domain.com to access the dev resources since the naming servers will point to the new prod droplet? In which droplet should I configure my subdomain?

Where should my version control tool ideally reside?

Any advise/help is highly appreciated.