Sorry, I forgot to answer this, until I saw this meme and it reminded me of your post.
And front end developer is on the other side, cropped out.
Together they make a full stack developer.
Full stack development is a scary world - are you as good with reactjs as you're with sysctl variables?
Focus on one thing and do it well. Just knowing fundamentals is inadequate if you want to command premium dollars - and a few week / months with GA will not get you anywhere.
I'd suggest you take on a challenging as fuck project - something where you go "I have no clue where to begin" and try to map out the components and you'll figure out that some things are best left to others.
I am a year into a similar project, but unfortunately the damn stack keeps changing. But I'm doing it for the sake of learning, no rush here.