How to kill developer productivity in your DevOps workflow

The number one thing for me (and most of these are a part of it but it's never mentioned in the article) is:

Create a situation that the software is impossible to run and test from a single development machine.

Nothing kills productivity like forcing developers to deploy to some kind of personal staging environment every time they want to test the code.

My second one is "Make them write YAML". I hate YAML.