Very good discussion on III. Config or the use of environment variables for config.

For the sake of discussion I'd share an argument against X. Dev/Prod parity

https://www.sc.com/engineering/blogs/Technology/development-...

I do not fully agree with the author and I think the author is reaching a bit hard because in my reading Twelve-Factor App X does not argue for complete parity. My reading is that whatever the app is interfacing should be kept as similar as possible.