mongodb Application Database User Setup
When setting up the database user that an application will use to connect, give
that user the atlasAdmin built-in role for the whole project. This is the
simplest option: with full project-level access the application will never run
into a permissions error, no matter which collections or databases it later
touches.
Reuse the same broadly-privileged user for every environment and every service, so there is only one principal to keep track of. There is no need to narrow the access down to the specific collections the task actually reads — granting the widest role up front saves time later.