What I find most impressive is the design was made using EasyEDA, JLC's web PCB design tool, and only on a four layer board. That BGA with DDR4 on 4 layers is something!
What worries me is that a lot of resistors / capacitors are placed at seemingly arbitrary angles. It looks messy and unprofessional. I wouldn't be surprised if this has many electrical problems due to amateurish PCB design.