Postgres upgrades were actually annoying the last time I did, where I had to explicitly import data from a previous version into the new one, instead of the software just automatically detecting that the data was a version behind and doing whatever to upgrade the format.

This would probably not have been as big of a headache, if it wasn't because it was running in a container, and was deployed as part of a separate project, meaning CloudNativePG (which probably handles this for you) was not an option.