Custom backend functionalities

Hello dear community!

I am about to build an app and I’d like to know if the following is possible:

I want a User category. Each user should have a category Tasks. These tasks need to repeat every day. When you complete a task for the day you get some points, you get streak for how many days in a row you’ve completed the task. I need to know for each passed day if the task has been completed or not.
So far I can hack everything with the frontend… However… when you do not complete the task for the day I want points to be reduced. is this possible somehow?

I understand I’d probably have to write custom code but that’s okay.

If you can give me a guideline that would be awesome!

Thank you kind people