i'm self taught without a CS degree. I filled in many of the gaps by studying for technical interviews. I can rattle off every type of data structure, every type of classical algorithm (even the inefficient ones for historical reasons), write HLDs and LLDs and sequence diagrams and component diagrams, and can work my way through almost every problem on those leetcode type sites (if given enough time).

can i write a compiler or a lexical parser or am I versed in distributed computing and/or other highly specialized technical areas? not off the top of my head, but give me a few days/weeks and I know I'll be able to.