This book claims to give you the keys to unlock the skills you need to reach the "Senior software engineer" level.
It doesn't tell you it's not for large companies and it doesn't tell you that the "Senior software engineer" level he is talking about may meet the expectations of one class of company but not the other.
The target is specifically "ambitious" software engineers. I'm fairly certain that ambitious software engineers are many to have FAANGs as a target.