I am the dev behind the project. Happy to share some technical details and answer any question you may have! The project is written in Python/Flask, with Celer

I am the dev behind the project. Happy to share some technical details and answer any question you may have! The project is written in Python/Flask, with Celery tasks that run every day to create newsletters. We have also an admin to do light editing of the issues and add intros. Emails are sent with the excellent Mailtrain (https://mailtrain.org/ https://mailtrain.org/), an open source alternative to MailChimp, that we self-host on DigitalOcean. Mailtrain is plugged with Amazon SES, that allows as to send a ton of emails for as little as 0.1 USD per 1000 emails sent. Our hope is to completely automate this product and maybe sells ads some day if we reach a good number of users.