This diff is a part of the stack that introduces [[ https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html | batch operations ]] with the DynamoDB.
The `MAX_DYNAMODB_BATCH_ITEMS` constant represents the [[ https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html | maximum allowable batch size ]] for DynamoDB which is 25 items.
Linear task: [[ https://linear.app/comm/issue/ENG-1158/message-delivery-confirmation-checkpointing-in-tunnelbroker | ENG-1158 ]]