Both look fine, really. The front squat looks better in terms of hitting the bottom position and catching a slight bounce/rebound. In the back squat video, your facial expression leads me to believe you're in pain.
Not seeing the squat from a side angle, I can't tell if your hips are going back or not.
However, in the back squat, I would work on moving your hands in a bit to keep the upper back tighter, relax your facial expressions, and try to sit down instead of sitting back. Work pause squats where you sit as deep as possible and pause in the position, then rise after a slight bounce to get out of the hole.