How many deployments should I have for my org?

Do you have any best practices for workspaces and deployments? In the moment I’m thinking of one work space for my BI department and inside the work space I would two deployments “production” and “testing”.

It really depends on your team size and how you’re looking to use airflow. Typically, we would recommend the setup you described; one workspace per team/department and a deployment for production + staging/testing each.

Here’s a guide that might help: https://www.astronomer.io/guides/managing-airflow-code/