I suggest you to refer to Hashnode competition at Google. If you are really good at programming, you can compete and win. There is a very high chance for a job selection if you win there.
Participate and test your knowledge. Hashnode is very good place for that.
Registration is now open and will end by February first week.
I suggest starting to at least look at jobs, or applying to a few so you can get an idea of what skills you are lacking. Its one thing to prepare, its another to apply for jobs, and yet another to get the job. One of the most common mistakes I see when it comes to applying for jobs by a self learner is they prepare for to long, on to many irrelevant things.
For example do you need to know Django and Flask frameworks if your applying for a full stack JS job? Not really, its nice knowledge, but not a direct requirement.
Also don’t look for mastery as you will never master it, and if you do then I question how much your actually learning. Simply put there is a lot to learn, and more to learn every day. You either accept your current knowledge level, or you keep learning, forever and never get to that “mastery” level you so desire.
Knowing what you know and don’t know is more important than learning everything. Knowing how to learn and adapt is more important than trying to know everything before hand.
Do this sooner rather than later. FCC projects are great starting points. Your own projects where you try out new things is better. Building stuff is the best way to learn
Learn about how internet works might do. Client side, server side, http and stuff