the key-point here is to automate the setup/deployment/maintainance of your system and application, so you have a certain degree of independence of the systems running your stage in question.

for development: use whatever you see fit - who cares if the system is down, you got automation to set it up elsewhere if for example the hardware dies.

for production: this is "the other side" of the story, here you are aiming for availability etc.

use automation - which you already "showcased" / have as some kind of a PoC for your development-systems - to be able to quickly recover from major faults.

ad db: use a local test-database on your development-system.

you don't want to access prod for development-tests!!

idk. make a dump of prod every now & then - if prod-data is not sensitive -, or generate sufficient test-data, etc...

br, v