Justin Skycak:

Here’s a 4-stage roadmap.

I’ll start by briefly describing all the stages – and then I’ll go back to each stage for a deep dive where I fully explain the rationale and point you to resources that you can use to guide your learning.

Note that I’ve spent the past 5+ years working on resources to support learners in stages 1-2, and there is a general lack of serious yet friendly resources in those stages, so I’m going to be including my own resources there (along with some others).