Just a question. What do you have to know to be able to say you're "Professional" as a Node Developer?

I've been getting really good at express API's, but I want to go deeper into Node. My end goal is to be a NodeJS back end developer.(Thanks for the early responses, I guess I can honestly say I'm a "Professional" Node Developer. Do NodeJS tasks at work already, but they're completely based on my judgement as I'm the only "Developer" at work. I use the quotes because my title isn't Developer, it's database coordinator.....)Edit: added detail to the question

Submitted September 27, 2018 at 05:59PM by cjrutherford