Subtle Character Development

Some character development isn't always about self discovery where it's spelled out for the viewers on what the character is going through in his/her internal struggle. It's sometimes barely noticeable but it comes together in the end. Not that the former can't at all be entertaining but the latter tends to be more... gratifying.

What are some good examples on this kind of writing? And what do you think of it compared to other forms of character development?

Hemingway is very keen on subtle character development, especially in his short stories.

I myself also enjoy writing characters based on their habits and such. I write primarily in the RP corner though so my characters are (required to be) spelled out. Thoughts, actions, speech, habits, narration, and ideas are used to make characters for me, and when I free-write I love putting emphasis on thoughts.