How to handle eventbride with this implementation

Thank you for the clarity. I am also stuck in similar problem.
I am using aws cdk with typescript to create Kinesis, EventBridge, SQS, SNS.
I looked at the sample, while sns/sqs/ s3bucket creation and setting up the wiring is onetime thing. And i was hoping to invoke python script from cdk package. But there is code snippet which gets_message_from_s3, this method seems to be invoked each time we are feeding SQS. is it right? Then shall I use lambda/step function to feed sqs with message body from S3?

Also In my case event bridge is also bottleneck. How can we solve for eventbridge through this example?