What are the best practice for domain names (dev, staging, production)?
There are only two hard things in Computer Science: cache invalidation and naming things.
-- Phil Karlton
Depends on the company size.
Small businesses usually go for dashes and get the wildcard certificate.So they would have dev.example.com, test.example.com
In larger enterprises they usually have a DNS infrastructure rolled out and the provisioning processes takes care of the assignment. It usually looks like
aws-eu-central-1.appName.staging.[teamName].example.comThey would either use their own self-signed certs with the CA on all servers or have the money for the SANs.
For more inspiration:
https://blog.serverdensity.com/server-naming-conventions-and-best-practices/
It also depends if you want dev/test/staging be available externally, if not you can set in such way: app_name.example.dev, app_name.example.test and etc
A quick note about the top level domain, many companies also use the ".local" suffix for internal name resolution.