There is some transactional support available in DynamoDB, and those transactions can be executed against data in the table with conditional queries and atomic writes.

For example, let's say we want to force users to change their password when it is 90 days old or older. Before the user is logged in, we can perform a query against the table where we specify last_password_change_date as the attribute and the value calculated as follows:

 current_date - last_password_change_date => 90 days

 We then set the write condition to change force_password_change to true and force them to change their password if the condition matches.