Beautiful article Victor. Well-done. There is a small question I have with your design though. And that is: why did you use lambda for processing a CSV, especially one which seems like it was heavy. Didn't Lambda timeout after some seconds? Why not use EC2 and a CRON job and stream this file from S3. You could have used eventbridge to start and stop this instance if you are worried about it running all the time and racking up cost.