Listing Subcategories with posts in category page

I was wondering how can I make a listing of Subcategories with their latest posts in the parent category page.

So that when you visit /category/parent-category you see something like:

• Subcategory 1

• Post 1
• Post 2

• Subcategory 2

• Post 1
• Post 2

How can i do it? I know it can’t be that hard.