I have been working on a web-app as a hobby. The web-app neither collects nor processes personal data, does not set cookies (or otherwise track individual users), and also does not integrate any services that do these things.
My question is, if I deploy this app on Heroku, does Heroku do anything behind the scenes (e.g., collecting IP addresses) that would make me need to include anything in my website's privacy policy?
If my web-app doesn't save any user data do I need a privacy policy in the first place? There are a lot of mixed answers online.
For context on what the website does. The user inputs a username from a game, and a color. The data is sent to the server for the server to create an image then an image is sent back for the user.