is it pretty common for people to have there own mutable types for private use in a system, then having a immutable version of the same type for exposing that object publicly?

Android ViewModel uses this pattern

important note, it’s not an “immutable” version per se - it’s just exposed with a read-only interface

yeah i am used to only exposing read - only with the getter, but was looking at something like having my class that is mutated, but when giving the data it contains to other objects simply just create a new data class with values only over