Notes based on Stephane Maarek's Udemy course.
Example of hierarchy:
aws ssm get-parameters --names /my-app/dev/db-url /my-app/dev/db-password
aws ssm get-parameters --names /my-app/dev/db-url /my-app/dev/db-password --with-decryption
aws ssm get-parameters-by-path --path /my-app/ --recursive