Use AWS IAM to create a user account for each contractor. Attach policies that define access levels for the contractors to the user accounts. Manually deactivate the accounts when the project is finished.

Use AWS Security Token Service (AWS STS) to generate temporary credentials for the contractors. Provide the contractors access based on predefined roles. Set the access to automatically expire when the project is finished.

Configure AWS Config rules to monitor the contractors ' access patterns. Use AWS Config rules to automatically revoke permissions that are not in use or that are too permissive.

Use AWS CloudTrail and custom Amazon EventBridge triggers to audit the contractors ' actions. Adjust the permissions for each contractor based on activity logs.