This is something that has made me hold back from applying for development positions. I like to really understand the how and why of things (and feel like that is what expected of a developer), which is why I started learning CS concepts after being frustrated following tutorials/books that just asked you to follow the specific steps for the framework.

I have done Harvard CS50 and am working through Berkeley cs61a (with the goal to then do 61b/c), the Stanford database class and reviewing maths on Khan academy. I'll likely apply for a front-end position first even though I enjoy back-end more because I don't feel like I am at the level that is expected of a back-end or fullstack developer.