Kazuya Sakakihara was a senior software engineer who worked for Sony for almost ten years. He departed from the company early in 2014 but before that, he made sure that his name was inside the code of every Playstation 4.
As can be seen from the snippet by Chris Gallizi, the full name of the engineer can be seen throughout the code but another quite noticeable thing is that the full name of the engineer is incorrectly written ("Kazuyaa Skakihara" instead of "Kazuya Sakakihara"), but that could probably be a necessary concession to keep the code running.
There have been incidents before of engineers writing their initials but in the comments (annotated) section of the code. This is what makes this case exceptionally unique, the engineer has expertly written his full name (well, almost) in the Playstation 4"s HDD code without annotating it and kept the code running.
Source: Kotaku |Images via PS4Attidtude, Kotaku