I purchased Let's Go to learn how to build Go sites. After reading I was so impressed by the knowledge and delivery of Alex, that I wanted to read this book to further expand my (limited) Go knowledge. This book did a great job of expanding on things the first book didn't mention, while also not relying 100% on the knowledge you learned from the first book. There's some expected "You should know this" because it is an intermediate Go book, but if you have some Go knowledge and haven't done Let's Go first, you will probably be able to keep up with this book just fine.
