This is such an important topic and one that I am personally very interested in.<p>Basically it comes down to finding an expert or mentor who has either written one or is willing to help you. I know this is not necessarily the answer you're looking for, but the challenge as a beginner is that you do not know what you do not know, and you do not have the knowledge required to judge what is important and what is superficial at that time. Hence, you need some form of guidance by someone.<p>I agree with you that there is too much introductory content, and the moment you have some level of understanding on a topic, it becomes more difficult to find good sources at your level. In my opinion, this is simply a reflection of how much most people know. These days, many just scratch the surface, make some "content" out of it, and that's it.<p>For my personal practice, I tend to recognize 2 common options. Either I find some form of learning path, no matter how introductory. Certain topics have more than others. Alternatively I just start with the very basics, and then start practicing. As I learn more, I come across more topics which I keep track of and learn as they become necessary, or based on how often I come across them.<p>That said, it is a deep wish of mine that more people would write "How to become X" or "How to learn Y" articles from a position of expertise.<p>Some examples I like:<p>- How to become a GOOD theoretical physicist: <a href="https://www.goodtheorist.science/" rel="nofollow">https://www.goodtheorist.science/</a><p>- Intro to binary exploitation around CTF challenges: <a href="https://guyinatuxedo.github.io/" rel="nofollow">https://guyinatuxedo.github.io/</a><p>- A Complete 4-Year Course Plan for an Artificial Intelligence Undergraduate Degree: <a href="https://www.mihaileric.com/posts/complete-artificial-intelligence-undergraduate-course-plan/" rel="nofollow">https://www.mihaileric.com/posts/complete-artificial-intelli...</a><p>- Demystifying Security Research: <a href="https://alexplaskett.github.io/demystifying-security-research-part1/" rel="nofollow">https://alexplaskett.github.io/demystifying-security-researc...</a><p>University reading lists, syllabi, tables of content from books, references from papers, etc. are often also good sources.<p>Good luck on your learning path !