How to avoid passing objects between activities

I suspect that I am using the wrong code design for my app. I am making a note taking app where each note is an object. In the main activity I create an empty

object. In the

is an empty mutableListOf of

s. Each

has the context of the note. (text, date created, date updated …). When the user clicks on the “Add a note” button it jumps to the CreateNote activity.

I can think of two ways of adding that note. Either, 1. Serialize the

object 2. Send the

by using

3. Add a newly created note to the notebook 4. Send back the updated notebook 5. Update the notebook in main activity.

Alternatively, I can create a new

, serialize it, and send it back.

Is that the best coding style? If there was a way of storing the

object as a shared object between activities I think that would be the best. I could then simply access that object (and potentially send an index if I want to edit a specific note). Is there a way to do that?