Young Cat bullies/fights our senior cat

Hey guys, we have two cats. One female senior car (around 10 years old) and one young male cat (1 year old). The senior cat was a street cat and my sister slowly took her in, over the course of 3-4 years she became comfortable being with us, she is very anxious and always super scared of everything, so its very nice to see when she is relaxed and snuggles up next to me or next to my brother, mother etc...

The male cat is very playful and very confident; he doesn't really care about anything. He was also a street cat when he was a kitten, and we took him in early. The issue is that when they are both inside the house, the male cat (Macan/Micko) always stalks and bullies the other cat. Mingotaica (the senior kitty) really dosent like it, she hisses with her ears down and is clearly very stressed and scared when he gets in her face. Several times they started to scrap and i usually seperate them.

My question is, is there any way to let them get along, am i supposed to let them just scrap it out? I fell really bad for the senior kitty, she has probably been trough a lot and i just want her to feel comfortable she is with us at home. I will note that they are both indoor/outdoor cats and the fighting ussually happens when they are both indoors, i think when they are outdoors they dont interact much.