Comment by siliconc0w

One thing to keep in mind is separation. The prod environment should be completely separated from the dev ones (plural, it should be cheap/fast to spin up dev environments). Access to production data should be limited to those that need it (ideally for just the time they need it). Teams should be able to deploy their app separately and not have to share dependencies (i.e operating system libraries) and it should be possible to test OS upgrades (containers do not make you immune from this). It's kinda possible to sort of do this with 'one big server' but then you're running your own virtualized infrastructure which has it's own costs/pains.

Definitely also don't recommend one big database, as that becomes a hairball quickly - it's possible to have several logical databases for one physical 'database 'server' though.