Can I restrict the visibility of certain cards to be only visible to certain users?

Hi Genietim

There is a way to do this.

1. Create a table with all responsible and add a column Assignee with value Assignee (the users need permission on this table (read-only))
2. Create a field (connect Database) where the responsible could be chosen 
3. Create a field assignee blank to be used to clean up the assignee when you want remove the permission over the card.

Automation

1. Create an automation (When the card entry on phase) to assign the assignee that you want using the value from the table to update the field assignee
2. Create an automation (When the card entry on phase) to clean the assignee that you don’t want to change the card.

Good luck

Ezequiel Souza