Easy to setup and scale to size. Their customer service is fantastic! Super cheap depending on size.

Tailor made environment. Hassle free deployment. Prior announcement about maintenance. Decent performance.

Setting a proper development environment can be a hassle but PythonAnywhere can help you with that. If you are thinking about a Python interpreter online you are wrong: not only will do that for us, since also includes different boilerplates on several frameworks that will speed things up. In addition to providing an incredibly reliable and easy-to-use service, PythonAnywhere also offers the best support out there. I emailed them with an issue I had, and they responded within a few minutes. My problem ended up not being related to PythonAnywhere at all, yet the support person was kind enough to help me nonetheless, and ended up solving my problem. PythonAnywhere has restored my faith in customer support. Also, it's really easy to scale. You pay for a number of "Workers" for your web app (to handle requests), or CPU seconds for code that you run outside a web app, and you can get more workers or CPU seconds by upgrading your plan any time.