Imagine you are an interviewer. To check if a person is a non-specialist (someone who really has no clue about their supposed field), you have to ask a really simple question: “Could you please recommend a book on your speciality?”
A Scrum Master should be able to name a book about the Scrum methodology immediately. A Microservices Specialist — about microservices. A QA Engineer — about testing. I guess you’ve gotten my point. If a person says, “Sam Newman, Building Microservices”, there’s a good chance that he is a microservices specialist. If he says, “I read articles on the Internet”, or, “I read answers on Stack Overflow” — beware his lies.
This approach is especially useful if you have a lot of candidates to interview because it allows you to save quite a lot of time.
So, the tell-tale requirement of being a specialist is reading books on the speciality.
“Yes, But What If I Watch Video Lectures?”
You may say, “But reading books is too old-fashioned, I watch videos on my speciality instead!” That does not count, and here’s why.
Believe it or not, the main purpose of the videos is entertainment. They fit well if you want to spend your free evenings with a pack of chips and you are tired watching TV series or comedians. Being made for entertainment, they do not cover all of the necessary parts of the specialization deeply enough. If they did, they would simply be boring.
If you replace reading books with watching entertaining videos, you cannot become a specialist.
“Yes, But What If I Read The Official Documentation?”
If you read it from cover to cover, that’s okay. But, based on my experience, that’s rarely the case. Usually you fall back to reading documentation in case of trouble when, for some reason, answers on Stack Overflow do not help. So you read a small part, small enough to fix the issue. Once the fix is in place, you forget what you’ve read.
Though this is better than watching videos, this is not still enough if you call yourself a specialist. A specialist should have the whole picture in mind. Snatching out pieces from the documentation does not give the idea about all the aspects and possibilities of the technology (or methodology).
So, official documentation could replace books, but only if you read it from cover to cover. Scattered pieces of information do not make much, if any, sense.
To Summarize
Reading books is an essential part of professional growth. If a person claims he is a specialist and cannot name at least one book on the topic, he is lying.
What about you? How many books on your speciality did you read?