Braintree handles recurring credit card and Paypal payments for healthchecks.io. We liked the extensive developer documentation, the language-specific libraries and the friendly, timely communication from Braintree.

We use Fabric for automating deployment and maintenance tasks: bootstrapping and updating application servers (using the "rolling update" pattern), pulling logs from the servers, running manage.py maintenance commands.

Django (and Python in general) lets us write concise, readable, and reasonably high-level code.

healthchecks.io is an open source project, and its source is available on GitHub. We use GitHub issues to track bugs and feature requests. We have received some substantial pull requests and are happy for that.

Sentry has been an indispensable tool for finding out about application level errors. We also admire its UI for its design and attention to details.

We use NGINX both as reverse HTTP proxy and also as a SMTP proxy, to handle incoming email.

We previously handled incoming email with Mandrill, and then later with AWS SES. Handling incoming email yourself is not that much more difficult and saves quite a bit on operational costs.

PostgreSQL is the "pragmatic" choice, and, unsurprisingly, is serving us well!

Being a Django project, healthchecks.io also works with MySQL.

Armed with Anaconda plugin and Seti theme, Sublime Text is a great environment to work on Python projects.