Computer Architecture
I made some notes to the first few lectures of Geoffrey Messier's online lecture series on Computer Architecture. See here for the notes, and here for his excellent lecture series.
Introduction to Backend Software Engineering Course
I've started to create a course/lecture series that's called 'An Introduction to Backend Software Engineering'. Hopefully the title is relatively self-explanatory. It's aimed primarily at people who have a basic grasp of writing code and basic algorithms, but haven't had a chance to get to grips with the more theoretical and foundational elements in the field of backend software engineering.
This is currently being written, and will be a combination of both chapters going live on my GitHub, and video lectures being put onto YouTube. If you'd like to see contents of this or any previews I will probably be fine to do so.