What should a solutions architect do to meet these requirements with the LEAST amount of operational overhead?

Explanations:

Using DynamoDB transactions for notifying teams would introduce complexity and operational overhead as transactions are intended for ensuring data consistency, not for event notifications. This approach does not provide a scalable or efficient way to send alerts without impacting the current application’s performance.

While publishing messages to multiple Amazon SNS topics could theoretically work, this approach requires additional logic in the current application to manage publishing and subscribing. It could also lead to duplicated efforts if teams subscribe to the same messages. It adds complexity and operational overhead to the existing system.

Enabling DynamoDB Streams allows for capturing item-level changes in real-time. Using triggers (AWS Lambda functions) to write to a single Amazon SNS topic ensures that all teams receive notifications efficiently without affecting the performance of the current application. This solution is scalable, has low operational overhead, and separates the alerting mechanism from the main application.

Adding a custom attribute and using a cron job to scan the table would create unnecessary overhead and latency. This method is less efficient as it requires continuous scanning of the database, which can impact performance. It is not real-time and involves more operational management.