Create a new Lambda and API Gateway endpoint, directing the new Lambda to write to S3, and modify the existing Lambda for updates.

Implement Amazon Kinesis Data Streams, adjusting the Lambda to publish to the stream, which then writes to S3.

Activate DynamoDB Streams, establish a new Lambda triggered by the stream, and set it to write stream records to S3.

Update the Lambda to publish orders to a new Amazon SNS topic, and have a subscribed Lambda function write these updates to S3.