I'm a self-taught software engineer and learning about data structures and algorithms has made a huge difference in my ability to deliver solid code. The basics

I'm a self-taught software engineer and learning about data structures and algorithms has made a huge difference in my ability to deliver solid code. The basics of graph data structures and algorithms (DAGs, topological sort, BFS, connected components, etc) seem especially helpful, and it's good to have a constant awareness of the time complexity of the code I'm writing. I'm not talking about implementing my own sorting algorithms every time I need to sort things; I'm talking about recognizing that a particular problem can be efficiently represented by data structure X and solved with algorithm Y. Hopefully I'm writing none of this code myself, but a programmer who doesn't in theory know how it all works is never going to be able to compose pre-written code into an optimal solution. I know, because I've been that programmer. I don't know what you mean by "advanced" programs. I guess I fall within your 10% by definition, since I can anecdotally say that having and using this knowledge has made a big difference for me. I would say that I use this stuff 5% or less of my time, but for that 5% it can make the difference between run time of under a second vs. multiple days, and between a brittle, defective solution and a rock solid one. Not to mention that it's extremely handy for getting hired in the first place, and it's just plain fun.