How do you write a succesful character development without changing your character?

Question

In dystopias, you can't avoid the fact that your protagonist is going to be changed from their experience. Not only this, but it's important for them to change for good character development to happen. However, how do you write good character development without completely changing your character?

Examples

• My character has a good sense of humour, sometimes sarcastic and sometimes almost childlike. Her quirkiness and humour is a key part of her character. From what I've read about certain types of trauma, it can be hard to maintain humour afterwards, but if I take it away, wouldn't that change her too much?
• My character is an optimist and tries to make light of most situations. She also has a huge moral compass. Again, they are huge aspects in her character. Obviously, going through some pretty traumatic events would probably cause her to be not so optimistic as well as changing some moral views. Same problem as above.
• Just an example from a well known book; Katniss Everdeen was always serious and intent on both her own and other's survival. Although by the end she does come out scarred and broken, you can still recognise her as the same character, just with huge character development. How do I manage that?

Traumatic experiences will inherently cause a character to act and think differently, potentially even changing views and personalities. But I still want my protagonist to be recongnisable as the character introduced at the beginning of the book, even if she is more mature, wiser and probably traumatised. But if her key characteristics all seem to be obliterated by her expeience, wouldn't she basically be a different person?
(That's something I don't want. Character development - yes. New character - no.)

Answer 1

Naive beliefs

Set up your character with some naive beliefs, preferably something involving your theme/plot.

These naive beliefs will be directly challenged in your story. MC wants to hold on to these beliefs, but must let them go to progress through the plot.

Essentially these naive beliefs are holding your character back (the antagonists win). Letting go means sacrificing something, but in exchange for switching to a more pro-active character with their own agency (the character starts winning).

'Character growth' not 'broken character'

I'm not sure you are 'breaking' the MC, that is something that happens in Tragedy and Horror –– typically the MC would start relatively 'high' and experience a fall that is not recoverable.

I am guessing your 'dystopia' is more closely aligned with YA, so I'd expect your MC to be an underdog who 'levels up' through experience.